Inside Slot Tech Magazine June, 2001slot-tech.com/members/magazine/lores/june01.pdf · Inside Slot Tech Magazine ... Unlock the Mystery of Monitor Troubleshooting ... The horizontal

Inside Slot Tech Magazine

Slot Tech Magazine

Page 2 - EditorialInside Slot Tech Magazine

Page 4 - Introducing the MOSFETModern switching power supplies require transistors that are fast, fast, fast!

Page 8 - Understanding Coin Hoppers - Part IIMore hopper maintenance and repair.

Page 12 - Jammin' with Chris Hunt - Slot Tech Troubleshooting Tips

IGT PE+ Constant door open signalIGT PE+ Missing or overdriven colors on monitor.IGT PE+ No progressive pulse going to the overhead.IGT PE+ Bar poker not crediting when fed with billsIGT S+ reel slot. Handle won’t release when coin is insertedCheap pot adjusting tool (good for adjusting CC series comparitors)

Page 14 - PM Schedules and LogsPreventative Maintenance - Keeping track of what needs to get done.

Page 18 - Unlock the Mystery of Monitor Troubleshooting - B+ is the KeyThe most important measurement you can make is the B+

Page 20 - Who Are the Best Techs?What makes a good slot tech? What differing skills are required for the job? Howdo YOU stack up?

Page 24 - Taking Bill Validator Repair to the FloorEveryone does BV repair. Here are some important tips

Page 26 - Bill Validators and Preventative MaintenanceSticking to a preventative maintenanceschedule will enhance the performance ofyour bill validators.

Page 27 - Show Report - SouthernGaming SummitSnapshots from the show floor.

Page 28Subscription Form

June, 2001

Page 2

Slot Tech Editorial

Inside This Month's Slot Tech Magazine

Randy Fromm's

Slot Tech Magazine

EditorRandy Fromm

Technical WritersPete BachranFrank DursoBart HoldenJon Hughes

Chris HuntKinger!

Scott ReynoldsFrank Sutter

Michael ThomasAdvertising Manager

Dennis Sable

Slot Tech Magazine ispublished monthly bySlot Tech Magazine1944 Falmouth Dr.El Cajon, CA 92020-2827tel.619.593.6131fax.619.593.6132e-mail

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copyright 2001 under the Uni-versal Copyright Convention. Allrights reserved.

Randy Fromm

Slot Tech Magazine June, 2001

Randy Fromm

In the last of our three-partseries on semiconductors,we take a look at a special

type of transistor called aMOSFET. MOSFETs are usedin low voltage power suppliesas well as in the SMPS ofvideo slot monitors. If youhave a monitor or power sup-ply that's blowing a fuse, youjust might have a shortedMOSFET. How can you tell?

Turn to page 4 and see.

Preventative maintenance isan important part of casinoslot operations. Some of thesub-assemblies in a slot ma-chine absolutely demand it.Bill validators are one obvi-ous example. Neglect a billvalidator and you can watchyour acceptance rates droplike a rock. Replacing lamps,cleaning screens and reelsand vacuuming out the in-side of the machines are allimportant. It may be impor-tant for the operation of themachine. It may be impor-tant for the appearance of themachine. It may be simplythat it's no fun working in-side a machine that's coveredin a quarter of an inch ofnicotine laden dust.

For all these reasons andmore, a slot operation needsto schedule these tasks andto assure that they are com-pleted. Slot Tech Magazinecontributing writer FrankDurso presents us with acouple of nifty forms that canbe used to keep track of thejobs at hand. See PM Sched-ules and Logs starting on page14.

This month's Slot Tech Opin-ion is on the subject of slottechs and skill levels. Canyou quickly get to a problem,isolate it and repair it? Is itfun for you or do you struggle?How would you rate yourselfin terms of your skill level?Read Mike Thomas' opinionon page 20. Replys are wel-come and will be published infuture issues of Slot Tech

Magazine.

And speaking of bill validatorsand routine maintenance andstuff, Bart Holden has a knackfor the practical side of thismost important and oft-re-peated repair. This articlealone is worth the price of anannual subscription to SlotTech Magazine. See for your-self by reading "Taking BillValidator Repair to the Floor"beginning on page 22.

Of all the tests and measure-ments you can possiblyname, none is more impor-tant to the art of monitor re-pair than measuring the B+power supply. Find out whyand where to take this vitalvoltage reading beginning onpage 16.

Until next month, see you atthe casino.

Page 4

Slot Tech Feature Article

In the April issue of SlotTech Magazine, we spentquite a bit of time discuss-

ing transistors. We’ve dis-cussed how transistors work,how they fail, how to testthem with a meter to see ifthey’re good or bad, and howto obtain replacment compo-nents.

The transistors we have dis-cussed so far are technicallyknown as “bipolar” transis-tors. Remember that they aremade from type N (negative)and type P (positive) silicon.These two types of silicon areof opposite polarities. Two po-larities - bi-polar.

Although a transistor can beused in a number of differ-ent ways in many differenttypes of circuits, we have pri-marily looked at the transis-tor in its simplist operatingmode, that of a simple switch.When a bipolar transistor isused as as a switch, its op-eration is simple. When thetransistor is turned off, thereis no connection between thecollector and the emitter thetransistor. When the transis-tor is turned on by applyinga specific voltage to the base,the emitter and collector areconnected together. The col-lector and the emitter are the“switchy” part of a transistor.That’s where the main cur-rent flow (called the collectorcurrent) flows. When thetransistor is on, those twoleads are connected together.

Or are they? Well, not really.Not perfectly, anyway. In a bi-polar transistor, there is al-

Introducing the MOSFET


ways a little bit of voltagedrop between the collecterand emitter, no matter howhard the transistor is turnedon. It’s called Vce and it’saround .2v in a bipolar tran-sistor. Even when the tran-sistor is fully turned on (acondition called “saturation”)the collector and emitterleads are not perfectly con-nected together. There is al-ways a .2v drop.

So what? What’s the big deal?It’s just two tenths of a volt,after all. Well, very often itisn’t a big deal. We use bipo-lar transistors as switches inswitching regulator powersupplies in computers all thetime. There’s one on justabout every desk in theworld. The horizontal outputtransistor in a monitor is abipolar transistor as well.

But this Vce does present acouple of problems whenwe’re trying to switch largeamounts of current, very fastas we do in a modernswitched mode power supplyor SMPS. One problem is dis-sipation of excess heat. Let’stry to do this without lookingat the numbers but just as ageneral concept.

If there is a voltage drop,there must be a resistance atwork here. That’s Ohm’s law.Watt’s law tells us that ifthere is a voltage drop acrossa resistance, we must be dis-sipating power which, in thiscase, can only show up asheat. Since Watt’s law statesthat the power in watts isequal to the resistance mul-tiplied by the current, you

can see that high currentswitching results in manywatts of waste heat. That is,of course, why there is sucha large heatsink mass for theswitching transistors in acomputer power supply andwhy the horizontal outputtransistor in a monitor ismounted on a large heatsinkas well.

In addition to the excess heatgenerated by the presence ofVce, there is another problemas well. The same resistancethat generates heat also lim-its the speed of the device aswell. As the transistor turnson, it takes a finite amountof time for the primary cir-cuit to come up to “fullpower.” Part of what deter-mines that time is the resis-tance of the circuit. It’s asimple formula, called an RCtime constant. T=RC. That is,Time (in seconds) = Resis-tance (in ohms) X capaci-tance (in farads). That is nota misprint, by the way. That’s

Page 5Slot Tech Magazine June, 2001

farad not microfarad. Re-member that the unit of ca-pacitance is actually thefarad (named for MichaelFaraday) and when we speakof microfarads, we are talk-ing about millionths of afarad.

But where does the capaci-tance come from? There’s nocapacitor in the primaryother than the main filter ca-pacitor and that’s actually apower supply for the primarycircuit and has nothing to dowith the switching itself. Inthis case, it’s somethingknown as interlead capaci-tance. Everything has someminute amount of capaci-tance in it. Just a small pieceof wire, held near anothercomponent, will capacitivelycouple with it. Also, the in-ternal structure of a bipolartransistor is loaded withthings that add capacitive ef-fects as well. We’re talkingabout electrons and holesand the so-called “majoritycarriers” of the current hereso we’d best just leave it atthat for now.

Normally, these small capaci-tances have no effect on a cir-cuit at all. They’re just toosmall. But as the operatingfrequency rises, the time be-tween cycles gets shorter. Ifthe time constant formed bythe combination of the resis-tance of the bipolar transis-tor and the interlead capaci-tances of both the transistoritself and the rest of the cir-cuit is too long, the circuitwill become inefficient, dissi-pating vast amounts of wasteenergy as heat and destroy-ing the bipolar transistor.

MOSFET to the rescue

Enter the MOSFET to the res-

cue. The MOSFET (Metal Ox-ide Semiconductor, Field Ef-fect Transistor) looks exactlythe same as a regular tran-sistor. It comes in the sameTO-220 package that is famil-iar to everyone. (see figure 1)

But they are a bit different inother respects. The names ofthe three component leadsare different. In the transis-tor, the three componentleads are called the emitter,collector and base. In the FETthey are the source, drainand gate.

Although the names are dif-ferent, their functions aremuch the same. As discussedearlier, the major currentflow through a transistor isbetween the emitter and thecollector. It’s called the col-lector current. In theMOSFET, the same job ishandled by the source andthe drain. When turned on,the MOSFET closes thesource/drain connection,completing the circuit. Themain current flow in aMOSFET is called the “draincurrent.”

The remaining componentlead is the controlling ele-ment of the device. In thetransistor, the “base” leadcontrols the flow of currentbetween the emitter and col-lector. A small voltage on thebase will turn the transistoron. In the MOSFET, the con-trolling element is called the“gate.”

There are a couple of thingsthat make the MOSFET abetter choice for high-speedswitching than a bipolartransistor. One is that whenit’s turned on, it is reallyturned on. There is no volt-age drop between the drainand the source to speak of.

It is as if there was a shortpiece of wire between the two.

The switching characteristicsLike the bipolar transistor,the switching characteristicsof a Power MOSFET are de-termined largely by the vari-ous capacitances inherent inits structure. These are shownin Fig.2. To turn the device onand off the capacitances haveto be charged and discharged.The speed at which this canbe achieved is dependent onthe resistance (which is nowalmost nonexistant, espe-cially as compared to a bipo-lar transistor) and the cur-rent sinking/sourcing capa-bility of the drive circuit.MOSFETs do not suffer fromthe same capacitive problemswhich limit bipolar devicesdue to the way they’re con-structed. For most applica-tions therefore the switchingtimes of the Power MOSFETare limited only by the drivecircuit (which is practicallylimitless since very little cur-rent is involved here) and canbe very fast. Temperature hasonly a small effect on devicecapacitances thereforeswitching times are indepen-dent of temperature.

In Fig.3 typical gate-sourceand drain-source voltages fora MOSFET switching currentthrough a resistive load areshown. The gate source ca-pacitance needs to becharged up to a thresholdvoltage of about 3 V beforethe MOSFET begins to turnon. The time constant for thisis CGS (RDR +RG ) and thetime taken is called the turn-on delay time (tD(ON) ). AsVGS starts to exceed thethreshold voltage theMOSFET begins to turn onand VDS begins to fall. CGDnow needs to be dischargedas well as CGS being charged

Page 6 Slot Tech Magazine June, 2001

so the time constant is in-creased and the gradient ofVGS is reduced. As VDS be-comes less than VGS thevalue of CGD increasessharply since it is depletiondependent. A plateau thusoccurs in the VGS character-istic as the drive current goesinto the charging of CGD .

Testing a MOSFET

That’s an easy one. When youhave a bad MOSFET, it willbe shorted. I’ve never seenone that didn’t. It will oftenburn up due to the high volt-age and current that’s ofteninvolved in an SMPS. Tech-nicians, well-known for hav-ing a superb sense of humor,laughingly refer to a FET asa “Fire Emitting Transistor.”It will typically have a drainto source short but you mighteasily see a drain to gateshort as well. That will sendbig juice through the drivingcircuit so don’t be suprisedif you see some componentdestruction other than justthe MOSFET itself.

Unfortunately, a MOSFETdoesn’t do that whole juctiondrop thingy that we findwhen testing a bipolar tran-sistor. You don’t see any ofthe .7volt readings we usu-ally get when testing semi-conductors. Fortunately, theshorts mentioned above areobvious and easy to spot.

There is a way that you cansort of test some MOSFETs.Use your meter set to the di-ode test setting. If your meterputs out around 3 volts or so,it’s enough to turn on mostMOSFETs.

Connect the black meter leadto the MOSFET’s source.

Connect the red meter leadto the gate.

Now move the red meter leadto the drain. You should geta low reading. The MOSFET’sgate capacitance has beencharged up by the meter andthe device is turned on.

With the meter positive stillconnected to the drain, toucha finger between source andgate. The gate will be dis-charged through your fingerand the meter reading shouldgo high.

MOSFETS are rated by volt-age and current, just likeregular transistors. The volt-age rating you’re interested infor substitution purposes iscalled the Drain to SourceBreakdown Voltage BVDSS.The current rating is calledthe Maximum ContinuousDrain Current ID.

Sometimes you can tell therating of a MOSFET by itspart number. A typical partnumber is 20N10L. The firstpair of numbers refers to thecurrent rating. In this case,it’s rated at a maximum drain

current of 20 amps. The N in-dicates an “N channel” FET.Some FETs are of oppositepolarity. These are known as“P channel” FETs. The final2 digits indicate the voltagerating. The 20N10L is a 100volt MOSFET. The L suffix in-dicates that a “logic” level isused on the gate to turn theFET on.

Join some of the industry'stop technical writers as acontributor to Slot TechMagazine. For writer'sguidelines, visit the web-site at slot-techs.com


Slot Tech Feature Article Hopper Repair - Part IIBy Frank Sutter

There are a lot of thingsto keep in mind whenclearing a hopper jam,

and last month I began thelarger-then-expected task oftrying to list them in print.Since this is such an exten-sive project, lets tie right backinto it, shall we?

When the hopper has an es-calator, the coin chute willhave different characteristicsdepending on the manufac-turer. The problem will be thesame, however, because coinchute jams in every type ofescalator hopper from anymanufacturer will normallywiden the entrance to the coinchute. This damage will haveto be straightened out in or-der to prevent the hopper fromjamming again. The methodof repair, however, will be dif-ferent because the variousmanufacturers build theirunits differently.

In all types of escalator hop-pers, the coin chute openingshould be no wider then thethickness of one and a halfcoins of the denominationthat the hopper is using. Anopening of one and a fourthcoin thickness would be bet-ter. We’ll cover the restora-tion of the coin chute openingmore later, but while we’restill on the topic of stubbornjams, let me roll out a fewnifty tricks to remove the onesthat are REALLY stuck.

I’ll begin by saying that inthese difficult cases, there isno substitute for good ol’ fash-ioned elbow grease. I’m going

to share with you a few tricksthat might make the jobeasier, but in the end, youwill probably have to apply aconsiderable amount of

physical strength to get thejam cleared. The hopper mo-tor applies a surprisingamount of torque to the pin-wheel, and when the cointravel is impeded, and coinsbegin to shingle up at the jampoint, they can really wedgethemselves in.The primary method of free-ing a really tight jam is to rollthe pinwheel back one spot.Remember that if the hopperuses a brake, you will have tohold it in the disengaged po-sition so that the pinwheelhas a chance to turn. Do notrotate the pinwheel back farenough to allow coins to getunder the knife from behind,because this could bend theknife. Hopper brakes in gen-eral consist of a pawl to stopthe driveshaft, and a leverthat pushes the pawl to thedisengaged position when thehopper motor turns on. Thisworks because the disengag-

ing lever is pulled tight to thebody of the motor by the mag-netism generated within themotor when it turns on, andcurrent flows through it.Some hoppers, it should benoted, have no brake mecha-nisms, because they use aDC motor, and these unitscan stop the coin motion sim-ply by reversing the currentflow through the motor. Ifthere is a brake on yourjammed hopper, and it is notheld in the disengaged posi-tion, your force will be ap-plied to the brake mechanism,and not the jam.

If rolling the pinwheel backone place proves to be impos-sible, the next step would beto pry one of the jammed coinsfree with a flat-bladed screw-driver. (Fig. 1) In either ofthese brute force methods ofjam clearing, the idea is tomatch the force that drovethe coins into the jam, orbetter, to lower that forcethreshold by loosening thescrews. Therefore, the nextstep would be to loosen up allthe screws in the area of thejam, and then try to pry thejam free with your screwdriveragain.If the standard screwdriverpry still doesn’t do the trick,sometimes the lockingneedlenose pliers can be usedto nip the edge of one of thejammed coins, and yank itout of the jam like a badtooth. Even though consider-able strength will be requiredwith each of these methods,you’ll still be able to use onlyone hand because the other

Fig. 1Levering jam with a screwdriver.

Page 9Slot Tech Magazine May, 2001

will be busy holding the brakedisengaged. However, youcould use two hands if youcould hold the brake disen-gaged in another way. WhenI felt like I needed two hands.I would sometimes slip a largerubber band over the motorto hold the brake pawl againstit’s body. In cases where thatwas impractical, I sometimestemporarily wedged a tool

between the hopper brake andthe hopper base or shieldingto accomplish the same thing.Please don’t forget to free thebrake again when you havefinished clearing the jam, or ahopper runaway will resulton the first payout that thehopper tries to give. You canwrite me an email and ask mehow I know this is true.

With the brake held in place,it’s easy to pull the lockingpliers with both hands. Youcan also use the screwdriverto pry while you pull on thelocking pliers. With bothhands free, it’s also opens upa method to easily apply amatching force to that whichwedged the coins in place.

Using a large flat-bladedscrewdriver and a light ham-mer, and with the brake heldin the disengaged position,

tap the pinwheel against oneof it’s pins to roll it backwardjust a bit. (Fig. 2) It’s tempt-ing to really whack the screw-driver, because these stub-born jams can be really frus-trating, but I find that a con-trolled rapid series of lighttaps works much better.When you use this technique,you have to keep in mind thatdamage to the pinwheel canresult from too much enthu-siasm, so proceed with cau-tion. Also, be aware that thejammed coin, which is prob-ably bent or damaged, mayfall back into the hopper. Toallow for quick recovery ofthese coins, you might con-sider sticking a small piece ofblack tape to them before youuse this powerful jam clear-ing technique. Also, be care-ful not to roll the pinwheelback more then one place, orthere is the danger of coinsrolling under the knife frombehind. If this method of ap-plying enormous reverse forceto the jam fails to free it up,I’d be willing to bet that thereis another problem that isholding the pinwheel in place.

If none of these techniqueshave succeeded in freeing oneof the jammed coins with thebrake held in the disengagedposition, you might have totry removing the knife andthe coin chute cover. It’s nota good thing to have to disas-semble the hopper if a cus-tomer is waiting, but some-times this small amount canincrease your chances of free-ing the jam considerably.

Using any of these methods,or any time you free a coinjam, in fact, remember not toput the coins that you re-moved back into the hopper.

Most often, they were dam-aged before they becamejammed, but even if theyweren’t, it’s very likely thatthe actions that had to betaken to remove the jam hasdamaged them. It’s better tothrow them down the drop.

That about covers the tricks Iknow to free stubborn jams,so lets get back to that wid-ened coin chute opening thatI mentioned above. It’s simplephysics that two coins can’tgo into a space only bigenough for one. When theytry to force themselves in, thespace will be changed to theextent that they succeed. Thecoin chute is an importantpart of the coin ejection sys-tem, because it is the finalgatekeeper left to insure thatonly one coin gets in at atime. If it is bent, as is oftenthe case, and two coins areallowed in, the hopper willjam again.

On an IGT hopper with anescalator, the coin chute coveris part of the escalator as-sembly. These componentsare quite sturdy and reliable,but when coins have leveredthemselves underneath anddoubled up, they can bend aswell as any other brand. Thiswill leave the leading edgeturned up and fluted, andfrequently close to two coinswide or even wider. Thismakes the hopper much morelikely to jam again. As a fieldrepair, many technicians liketo narrow this opening with along handled flat bladedscrewdriver and a hammer.(Fig. 3) When a customer iswaiting, this is probably thebest idea, since it’s both quickand effective. but I have foundthat the resulting coin chuteopening acquires a chewed

Fig 2.Rolling pinwheel backwards


sort of look and a wavy lead-ing edge that just can’t begood. It should come as nosurprise that when this sortof repair has been done to acoin chute cover enoughtimes, the jam frequency onthat hopper will go up dra-matically. Sometimes, thesecomponents can be rescued,but more frequently, theyhave to be replaced.

When there is time to do along lasting repair to the hop-per, there are two techniquesI used to use to restore theseIGT coin chute entries. Thefirst is to remove the coinsfrom the hopper, and to re-move the plate mountedacross the hopper, allowingfree access to the coin chutecover. At that point, it is pos-sible to straighten the coinchute cover directly with ahammer. This technique isremarkably effective for do-ing a long lasting repair, be-cause it leaves an edge that is

far straighter then you mightbe able to achieve with ascrewdriver blade. However,you shouldn’t use this tech-nique on the floor becauseit’s a little bit intimidating forthe patrons.

If you find yourself in theposition of repairing a coinchute entry that has beenrepeatedly “quick fixed” withthe flat-bladed screwdriver,and has acquired thatchewed, wavy look, it is prob-ably a good time to restorethat leading edge. Now it prob-ably should go without say-ing, but I feel compelled tomention this anyway. NEVERuse this technique on thefloor, this is only in caseswhere complete disassemblyis required. This technique isto remove the coin-chute en-try piece entirely from thehopper, clamp it gently in avice, and clean up the dam-aged leading edge with a

hand-held rotary tool. Be-tween this technique andusing the hammer and a flatsurface to straighten out anybending that has occurred,you should be able to restorea like-new functionality to theworkpiece, and actually solvethe chronic jamming prob-lems that are commonlycaused by this condition.These repair techniques in-volve true craftsmanship andbefore you attempt them, youshould be very familiar withclearing hopper jams, andhave carefully studied what itis that a hopper might needto operate properly.

On some escalator hoppers,the coin chute entrance is aseparate, small, wedge-shaped plate held in placeover the coin path by twoscrews. These pieces some-times bend when two coinsget wedged underneath, butbecause of the simplicity ofthe design, they are quite easy

Fig. 3Straightening bent coin entry chute.

to remove and straighten righton the floor. If you feel thatthe piece will require a bit oftapping with a hammer tostraighten it out, feel free,but I found that two pairs ofsmall locking pliers are suffi-cient to bend the piece backinto perfect shape.

That about covers the coinentry chute, so it’s time toturn our attention to anotherchronic problem, the escala-tor. In my next article, I’lltouch on clearing jams thatoccur in this diabolical pieceof engineering, and how torestore these units to a like-new condition after damagehas occurred. I also hope totalk a bit about wiper adjust-ment, the infamous “frozenpinwheel” the free pinwheel,and other hopper topics aswell.

When I started this series, I

thought that three articleswould cover the fundamentaltopic of hopper jams, but Ican see now that three ar-ticles is just enough space totouch lightly on the majortopics! Just understand thatno amount of my writing andyour reading will ever makeyou an expert on hopper re-

pair. You simply must makea few jammed hoppers payagain to learn it. What I havepresented here are simply aset of ideas that a new techni-cian can keep in mind whenhe or she approaches ajammed hopper. Hopefully,the technician can have con-fidence that no matter whatthe problem is, he or she willbe able to make it pay again.

Till next time, keep ‘em run-ning!

- Frank [email protected]


Slot Tech Troubleshooting Tips Jammin' with Chris Hunt

Well fellow Techies” It’sthat time of the monthagain and I have man-

aged to rustle a few little gemstogether for your enlighten-ment. It seemed that my writ-ings came to haunt me in thepast few weeks with me beingable to put my experiences togood use. In last month’s issueI talked about the 7v fuse blow-ing on the IGT PE+ machine,well I got that one. It turned outto be one of the “hot” lamp feedsto the buttons that had chafedand shorted to the door caus-ing the 7v to go to ground andblowing the fuse of course! So,watch out for that one.

This month I will cover somesneaky processor board faultsfor you, so read on.

IGT PE+Constant door open signal

You are called to a PE+ videoand the onscreen message is“DOOR OPEN.” After checkingthe obvious (and the 7v fuse)enter the input test. If you arerunning later software, the doorsignal should be showing arapid 01010101 sequence (theencoded security pulse) whenyou close and latch the door. Ifthe state changes to a solid 1,the probable cause is a transis-tor on the processor board. Re-

move the board and locate Q5(2N3904) check it with a DVMand you’ll find its gone collec-tor-emitter short allowing theoptic supply to be on all thetime. Replace the transistor andyou’re back in business. It maybe worth checking the wiringaround the door area that feedsthe IR led to make sure thatthere are no shorts. For thoseof you who are babysitting theIGT S+ reel slots, look for Q26.

IGT PE+Missing or overdriven colorson monitor

You notice an IGT PE+ on thefloor with funky looking colorson the monitor. After trying aknown good Ceronix monitor,it’s still the same. The cause willbe on the processor board. Re-

move the board and locate Q21,22 and 23. Test them with adigital multi-meter (DMM) orother transistor tester to see ifthey are open or short. Ifshorted, you will have a domi-nant color overlay. If open,you’ll be missing red green orblue.

They are as follows: Q21=BlueQ22=Green Q23=Red. Thesegenerally fail if the monitorframe is not correctly grounded.If a “flashover” occurs, the highvoltage tries to find its way toground via the processor board,committing the homicide of theRGB video output transistorson its way. Look for machine en-try cards shoved between themonitor frame and the monitorshelf... Hey, stranger thingshave happened!

These are the three video output transistors on the IGTPE+ board. When you have color problems that are notrelated to the monitor itself, this is a good place to look.

IGT PE+No progressive pulse going tothe overhead.

This is a rare one but has beena pain for many slot techs Iknow. Because you are lookingat a peripheral system, you canbe misled easily. So you’ve beenthrough all the obvious stuff:connections to the machinemotherboard, pigtail harness-ing leading to the progressivecontroller, etc. You’ve evendropped a hundred coins in justto make sure that it isn’tincrementing.

Remove the processor boardand locate CR20 (1N4148 Di-ode). Using your (or yourbuddy’s) DMM, check to see ifit’s short circuited. This diodeis used as a damper to drainany back pulses (EMF) shouldthe machine be tied to an in-ductive device such as an elec-tromechanical counter. If itproves to be shorted, check itspartner Q18 (2N3904). It alsomay have failed. This circuit isalmost a repeat of the door in-terrogation layout.

IGT PE+Bar poker not crediting whenfed with bills

Lets take look at a problem Icame across a little while ago.It involves our old friend “TheBill Validator” AAAAGH! (Youknow it) An IGT PE+ refuses toaccept any bill. The BV will takethe bill, hold it in escrow forabout 10-15 seconds and thenreturn it. Check for BV commu-nication in the input test andwatch for a change of statewhen a test bill is inserted. Yes,the BV is communicating withthe processor. After you havedone your daily “Swaptronics”(see April, 2001 Slot Tech Maga-zine) by changing the head,transport and stacker can, and

if you were really adventurous(or desperate... ha ha) the pro-cessor board as well, it’s stilldoing the same #@%&**#@thing.

Try this... If you have access toa “Set 4” set denom chip, you’rehome and dry. After recordingall relevant meters, use the setdenom EPROM and runthrough the setup as pre-scribed. Bring back the gameand ...TADA! It accepts billsagain. If you have any aftermar-ket retrofit PE+ Drop in Bar ma-chines with the GPT BV system(ex CVB) this problem may bemore common.

IGT S+ reel slotHandle won’t release whencoin is inserted

You are called from your lunchbreak to an IGT S+ reel slot. Thecustomer is of a traditional na-ture and likes to “Pull thehandle” but complain that theycan’t. Of course, they refuse touse the “spin reels” button. Af-ter checking connections and

wiring, the culprit is most likelyQ16 (MAC3030) located on themain processor board. Just fora change, this is a TRIAC and ifyou read last month’s issueyou’ll know all about those.Once again, get the DMM (bynow your buddy is contemplat-ing charging you a daily rental)and check for odd readings, es-pecially across legs 1 and 2(MT1/MT2). There is an actual

output test but I cannot be sureof the group number as itchanges with different SPO pro-gram chips. The TRIAC is drivenby a triac driver IC (a whitepackage next to Q16) but it’shighly unlikely that this hasfailed.

Cheap pot adjusting tool (goodfor adjusting CC seriescomparitors)

Finally, I have included a pic-ture of a useful little pot adjust-ment tool you can make if you’reshort of a few pennies. Using alarge wattage high value resis-tor (>2W@1megohm) cut off oneleg. Flatten the end of the otherleg to about 3/32" or 1.5mm(Eurotechs!) with a small ham-mer on the back end of a benchvise. Put heatshrink over the legfor insulation. Because the legis copper, it’s “soft” on somepots and you won’t use a lot oftorque. The high value is to pre-vent being zapped if your fingertouches the cutoff leg end. Ofcourse, you can always insulatethis end with a larger diameter

piece of heatshrink tubing aswell.

Well guys (and girls, ‘causeyou’re out there too) keep upthe good work, stay busy andmost of all KEEP JAMMIN!

-Chris [email protected]

Page 14



These are the forms that Icurrently use for my mainte-nance schedule. The first formis given to each technician atthe beginning of every month.Each tech has a different jobbased upon their ability, workschedule or specific task theyhave for the given month.Knowing the capabilities ofeach tech is very importantwhen assigning a task. Eachmonth the tasks change fromtech to tech so each duty istracked on a month-to-monthbasis. The shaded areas ofthe sample form indicate thatspecific tech's work scheduleduring the month of April.

The second form is where Ikeep track of what has beendone for a 3-month period.Every time a tech completes abank of tasks, they mark thebank with the date and initialit. I can look at random on adaily basis to determine whois getting the job done andwho is slacking. I also do aperiodic check of the bank toassure that the work is donecorrectly and to my stan-dards.

This seems to work well at mycasino as long as the mainte-nance task fits the tech andthe shift they have to work

(Obviously I can't assign atech who works a Friday nightshift do maintenance onmonitors on the floor. It's justtoo busy.).

Hope this may help someone.It works for me at the mo-ment. If other Slot Tech Maga-zine readers know of any otherway to accomplish this, I re-ally would love to know aboutit.

-Frank [email protected]

PM Schedules and LogsBy Frank Durso


Slot Tech Feature Article Unlock the Mystery ofMonitor Troubleshooting

B+ is the Key

Of all the tests andmeasurements youcan possibly name,

none is more important to theart of monitor repair thanmeasuring the B+ power sup-ply.

If you have a monitor with ablank screen, your problemmight be in the B+ powersupply. If your monitor takesa long time to come on andhas a dim picture, you mayhave a bad B+ power supply.If your monitor has a picturethat’s doing the hula, you al-most certainly have a badpower supply. If your moni-tor comes on for just a frac-tion of a second and shutsitself down, you probablyhave (you guessed it) a B+power supply problem.

Most monitors, regardless ofmanufacturer, have onemain power supply of be-tween +88 to +136 volts DC.This is the power supply thatdirectly provides the operat-ing current for the high-cur-rent circuits in the monitor.Specifically, this power sup-ply, known as the B+, pro-vides the operating currentfor the two deflection circuitsand the high voltage unit.These are the highest currentcircuits in the monitor, ac-counting for more than 80%of all the power consumed bythe monitor. REMEMBERTHIS FACT, as it will explaina lot about monitor trouble-shooting, as you’ll read later.

The term “B+” is actually athrowback to the old radiodays when all radios werebattery-operated, vacuumtube sets. They requiredthree types of batteries foroperation. A low voltage “A”battery provided power forthe tube heater filaments, ahigh voltage “B” battery pro-vided positive voltage for thevacuum tube’s “plate” supplywhile a moderately rated “C”battery provided a negativevoltage for the vacuum tube’s“bias” supply. When powersupplies replaced batteries,we held on to the term “B+”as an indicator that this isthe main power supply forthe set (radio or television.)

What’s Normal?

One of the keys to success-ful troubleshooting is to knowwhat’s normal. The best wayto learn this is to measure theB+ voltage every time youwork on a monitor. This may

seem like a waste of timewhen you have a problem likea missing color or verticalcollapse (which couldn’t pos-sibly be caused by B+ prob-lems) but it serves to rein-force both the methods of ob-taining the measurement andthe meaning of what is a nor-mal voltage for the B+.

As mentioned earlier, normalB+ voltages are typically be-tween +88 to +136 volts DC.This will vary between manu-facturers and models. Also,there are two types of powersupplies we now see in moni-tors. The majority of monitorsnow on site use a “linear” or“conventional” power supply.Modern designed monitorsuse a “switched mode” powersupply or “SMPS.” You caneasily recognize a monitorwith an SMPS by the yellow,ferrite-core power trans-former mounted on the PCboard. Monitors with linearpower supplies typically aretransformerless, “hot-chas-

sis” types.



Where to Measure the B+

A schematic diagram is aw-fully important when work-ing on monitors. Althoughthere are similarities betweenmonitor designs, no two areexactly the same. Having theschematic diagram helps alot because the B+ is gener-ally labeled at the output ofthe power supply. Even if itdoesn’t say “B+” it will gen-erally be labeled with the volt-age.

If you don’t have a schematic,here’s how to locate and mea-sure the B+ in just aboutanything:

SMPS - Find the yellow powertransformer. The outputwindings (the secondarywindings) will be connectedto diodes and electrolytic ca-pacitors. Just follow thetraces on the bottom of theprinted circuit board. Theseare the output rectifiers andfilter capacitors of the powersupply. In most monitors, thevalue of the filter capacitorwill be around 200 microfar-ads at 160 VDC. This mayvary somewhat. The voltageacross this capacitor is the

B+ voltage you want to mea-sure.

But it is inconvenient (not tomention potentially danger-ous) to measure the voltagehere on the bottom of thePCB, with the board proppedup and the power turned on.Instead, with the powerturned off, follow the tracefrom the positive lead of theoutput filter capacitor as itmakes its way across the bot-tom of the PCB connecting allof the components and cir-cuits that require B+ power.Find a component lead con-nected directly to this B+trace, where it will be conve-nient to measure the B+FROM THE TOP of the PCB.Now flip the chassis backover into its normal operat-

ing position and apply power.Connect your digitalmultimeter’s black lead to thechassis of the monitor andthe red meter lead to the con-venient test point you just as-certained. Use your DMM tomeasure the DC volts. That’syour B+ voltage.

Linear Power Supply - Notquite as standard as theSMPS, there are a couple ofways to locate the B+ testpoint in a monitor with a lin-ear power supply.

The quick way is to look for alarge, ceramic, wire-woundresistor with a value of 150to 330 ohms at 15 to 25watts. It will often bemounted on the side of thechassis, affixed by a mount-ing bracket to the heatsink.

This is a “shunt” resistor thathelps carry some of the cur-rent so the voltage regulatordoesn’t have to work so hard,lowering the voltageregulator’s operating tem-perature. This is an excellentplace to check the B+ powersupply. One side of the resis-tor is connected to the inputof the voltage regulator; the

other is connected to the out-put of the B+ voltage regula-tor. Simply connect yourblack meter lead to the chas-sis and with the power ap-plied to the monitor, use thered meter lead to probe firstone side of the resistor, thenthe other. The side with theleast voltage on it is the B+output.

If there is no shunt resistor,look for the voltage regulatoritself. If this is an IC voltageregulator, it will often carrya part number like“STR3123” or “STR30130.”The last three digits indicatethe output voltage of theregulator; thus you wouldexpect to measure +130 voltsat the output pin of the de-vice. If you do not have aschematic that indicateswhich pin is the output pin,simply check them all. Withthe power turned on and theblack meter lead connectedto the monitor chassis, care-fully probe each pin of theregulator. One will be B+ out-

put. KNOWING WHAT’SNORMAL, only one pinmakes sense as the outputpin.

WARNING: There is an EX-TREME danger of slippingwith your meter probe whenmaking this measurement. Ifyou aren’t 100% certain youcan make this “power-on”measurement without slip-ping and letting the smokeout of a bunch of compo-nents, it’s better to connectyour meter probe with thepower turned off using a cliplead then apply power andtake the reading off themeter.

Another, “power-off” way tolocate the output pin of thevoltage regulator IC is to setyour meter to the continuitybeeper or lowest resistancescale, connect one meter lead(either one) to the collector ofthe horizontal output transis-tor and probe each pin of thevoltage regulator with theother meter lead. The meter

will beep or show an ohm ortwo when you hit the outputpin. Of course, this only lo-cates the output pin of thevoltage regulator. In order tomeasure the B+, you mustconnect your meter, applypower and make the mea-surement.

If you’re working on an oldermonitor that uses discretecomponents (individual tran-sistors, diodes and resistors)instead of an integrated cir-cuit voltage regulator, thetrick with the big shunt re-sistor often applies as well. Ifyou do not see the shunt re-sistor, the B+ can usually befound at the emitter of the se-ries-pass regulator transis-tor. This transistor will al-ways be the largest one in theregulator circuit. Typically it’sin a TO-3 package.

In Next month's Slot TechMagazine: Associating B+readings with specific moni-tor failures . . . How to pin-point your troubleshootingbased on B+ measurements.

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Slot Tech Opinion Who Are the Best Slot Techs?By Mike Thomas

How good are you? Areyou the best? Do youhave what it takes to

be the best? Are you on theright path to success? Oddsare if your reading this ar-ticle, furthermore this maga-zine, you’re interested in theanswers to these questions.I often found myself wonder-ing, “What do other techs do?What are they capable of?”

I take pride in my work andanyone who does, needs areference; something to judgehimself against. Let’s face it,what makes you a qualitytech in your casino mightmake you a “super tech” inanother but a junior tech inthe next. I have had the op-portunity to meet a lot oftechs in the last couple ofyears. Some have made mefeel like a slot god while oth-ers have made me feel like aslot goof.

To get started, you have todefine what a slot-tech is.You have to consider the dy-namics of being a slot-tech

and determine the commondenominators among them.It’s not just about being ableto fix anything and every-thing. That helps but thereare many more factors thatare often overlooked.

My definition of a slot-tech isas follows: slot-techs mini-mize down time of all slot ma-chines, execute slot moves inan efficient manner andmonitor proper operation andconduct repairs on associ-ated player tracking equip-ment.

I think the simplicity of thisdefinition most appropriatelystates what is expected oftoday’s slot-tech. Some of youmay think this definitionleaves out some very impor-tant points such as preven-tative maintenance, compo-nent level troubleshooting,and repair of card shufflers,coin sorters or jet sorts etc.The fact is that most casinosdon’t ever do any preventa-tive maintenance. Howeverimportant it may seem, mostcasino directors don’t believethe importance justifies theextra cost in staffing to beable to conduct a full scalepreventative maintenanceprogram.

Next, I don’t mention compo-nent level troubleshootingbecause if you’re at that level,you would typically betermed a bench tech, not aslot-tech, therefore factorslike machine moves don’t

even apply to you. The mod-ern slot tech is not affordedthe time, resources or train-ing to perform a lot of indepth component level re-pair. “Quick” component levelfixes are a must though, likeknowing which diodes orwhich capacitors typically failto cause your monitor’s pic-ture to shrink or yourcomparitor to accept any-thing for credit. It’s greatwhen you work at a casinowhich affords you the oppor-tunity to work on cardshufflers, jet-sorts, andsignage but these aren’t themost important. It’s all aboutthe slots. Hopefully by nowyour asking “Upon what mer-its should I judge myself ?”

How do you fix a slot ma-chine? Do you use a logicalapproach or just stab aroundhoping to find a cure? I’mtalking about Diagnostics ofcourse. The single greatesttool slot techs can possess istheir ability to use machinediagnostics. I like to think ofthe machine’s diagnostics asgetting the machines opinionof how it’s operating.

Here’s a good and simple ex-ample: When you approachan IGT S-plus machine that’snot accepting coins, what doyou do? Do you open thedoor, change the coin, blowout the comparitor, close thedoor and try to feed it a coin?Or, do you open the door per-form a quick visual inspec-tion, then immediately go to

Cont -

output test 34 to see if thecomparitor’s getting powerand to test it with the dooropen. Luckily, due to the pro-liferation of video machines,IGT vision games and moresophisticated front displayson your newer, sigma typereal games, it has becomeeasier and easier to use di-agnostics. The days of carry-ing diagnostic referencecards for each game type onthe floor are luckily comingto an end. All the more rea-son to familiarize yourselfwith built in machine diag-nostics. When you approacha machine and you’re notsure what the problem or thecure may be, go to the diag-nostics. Every good techknows that this is the firststep to success.

Bill Validators are the nextarea that every great techneeds to be familiar with. Doyou know how to calibrateJCM DBV 200 or WBAheads? Yeah that’s an easyone. What about a DBV 145head where you must utilizeyour ability to use an oscillo-scope and a Digital VoltMeter? You should also befamiliar with repair and cali-bration on some of the othermajor bill validators such asMars and GPT. Most techni-cal managers look for techswho are skilled at billvalidator maintenance be-cause this is a very high pro-file job in most casinos. Thisis the source of a lot of com-plaints by customers and of-ten everyone in the slot man-agement team monitor theoperational status of the bill


validators. With the low de-nomination, high line bettrend in the industry, billvalidator maintenance hasbecome more and more im-portant. Unfortunately it isn’tappealing to a slot player toinsert ninety nickels in a slotmachine, unless of coursethey’re only at your casino toget as many free drinks aspossible from the cocktailwaitress.

Speed Through Good Judgment

Yeah, you can fix a serioushopper jam in a Williamsslant top but how long doesit take you?

This is what fellow Slot TechMagazine writer Bart Holdensays about being a great slottech: “I try each time to clearthat hopper jam faster thanthe last. I try to shave sec-onds off the time it takes meto set up the daily slot tour-nament...”

Being a slot tech means notonly taking pride in the com-plicated repairs but thesimple day-to-day ones aswell. I once worked with a slottech that could fix anythingbut no matter what the re-pair was, it took him an in-credibly long time for eachone. If you have an excellenttech who fixed five of thetoughest repairs in one nightand a less experienced techwho fixed 15 which hadsimple problems, who’s morevaluable to you?

Slot machines are worthnothing to a casino whenthey’re down. Sure, you andyour co-workers can keep the

machines running on a Fri-day night but what if your co-workers called in sick? Wouldyou be able to support thefloor successfully on yourown? To do this, a slot techmust exercise good judgmentand efficient repair proce-dures. This tech must be ableto forego a more interesting,time consuming repair on abusy Saturday night in orderto pay attention to the hop-per jams, BV jams and faultycomparitors if it’s in the bestinterest of overall floor opera-tion.

Slot Moves

At this point I find it neces-sary to talk about a slot pro-cedure most of us wouldrather not think about nortalk about. A lot of techs Iknow would refer to the fol-lowing phrase as cursing,that is “Slot moves.” From theslot directors’ and managers’point of view, this isn’t a bigissue. To them, it’s merelynumbers and letters movingaround on a page. The slotmoves are just experimentsto them on attempts to im-prove numbers and percent-ages. To a slot tech, it’s awhole different beast. Afterall, slot techs don’t spendtheir time snugly lining upbases, carefully placing themachines in perfect rows,skillfully wiring up auxiliaryand drop compartmentswitches to look clean andreduce the chance of acciden-tal disconnection just to ripthese same machines fromtheir homes and move themto the other side of the ca-sino two months later, but wedo.

We can’t change this so thegreat tech embraces it. Heenvisions the slot moves andfocuses on the most logicalapproach. A great tech is inthe type of physical conditionto withstand dropping andlifting thirty machines in hisshift if he’s required to. Thephysical demands on a slottech are getting greater; themachines aren’t getting anylighter. The video monitorsare making them heavier, themanufacturers are makingthem taller and wider, add-ing wheels, extra displaysand more extravagant bonusrounds requiring more andmore parts. A great techtakes pride in the efficiencyof the slot move and his abil-ity to lead the move.

I left my thoughts on playertracking for last. The reasonis that some of the best techsI know are reluctant to focuson this area with as muchattention as it requires.Player tracking systems arebecoming very user friendlyand great tools for billvalidator maintenance andmany other repair issues. Inthe future, slot techs will uti-lize the resources in thesesystems more and more toincrease the efficiency withwhich they perform theirjobs. A great tech uses thistool to it’s full potential. Thistech knows that with thissystem, you can find BVs notaccepting or with poor accep-tance. Inoperative card read-ers and door switches arejust a few more. For example,on the Bally SDS system youwrite basic programs to tai-lor your reports and displaythe specific data you need. I

Slot Tech Magazine

see a lot of great older tech-nicians allowing the youngerones to outshine them in thisarea due to their intimidationwith the computer systems.

I offer the above notes formany of you to considerwhen evaluating your ownperformance. I certainlycould have mentioned othervariables such as customerservice skills but let’s face it,everyone in a casino shouldexcel at that. Componentlevel repair techs are greatand if your casino offers youthe opportunity to developyour skills in this area thenyou are very lucky.

I wish all casinos would con-sider hiring and trainingtechs to repair power sup-plies, monitors, and all theother associated electronics.I believe the ability to savemoney with in house repairto all these electronic compo-nents is strongly underesti-mated by many in casinomanagement.

That doesn’t mean you can’tsearch for opportunities inyour spare time increase youreducation. The great tech re-members that all the skills heacquires at the casino,whether on the clock or not,are his to keep and take withhim. Slot techs are very for-tunate to work in such agreat atmosphere while per-forming jobs where you learnsomething new almost everyday that will not only makeyou a great tech at a casinobut translate to many otherindustries as well. A slot techis fortunate that their job is

by far the most costly to trainof any job in the casino, whileat the same time a tech ac-quires the greatest amount ofskills as well.

- Mike [email protected]

The TThe TThe TThe TThe TechFechFechFechFechFestestestestestis coming . . .is coming . . .is coming . . .is coming . . .is coming . . .



Bill validator (BV) failurecan account for a substantial loss of revenue

on the casino floor. On adaily basis, I see potentialcustomers approach a game,try to insert a bill, and walkaway shaking their headwhen the validator fails.While there are many typesof validators in the industry,I will be focusing on JapanCash Machines’ (JCM) WorldBill Acceptors (WBA) and Dol-lar Bill Validators (DBV).However, much of what willbe discussed applies to otherBVs as well. This is a guideto successfully decreasingthe amount

of down BVs on your floor.

REQUIRED TOOLS ANDPARTS

You should get a tool cart orsome sort of cart to transportyour tools. You will need tograb some spare hardware(latch pegs and guide pegs)for your cashboxes. You cangrab some Loctite, a rivetgun, and a few handfuls of1/8-inch buttonhead rivetsfor a tip I’ll share with youlater. Take a few spare BVheads, power supplies, andtransports to swap out anyfaulty parts on the floor. Ifyou have a problem with slotmachine doors gettingslammed on you harnesses,grab some spares. If you areallowed to do so, make a testcashbox for each type ofvalidator to bring along andsome sticky labels to tag badcashboxes so they can be re-paired after the next drop.Sign out some cash to testthe validators and we’reready to get on the casino

floor.

GETTING STARTED

Once you determine avalidator is not accept-ing bills, you will need toask yourself a few ques-tions. Is the head takingthe bill in and rejectingit? Or is it not pulling thebill in? If it is rejectingthe bill, try to clean thesensors and rollers. If it

will not take the bill you willneed to check your power sup-

ply and inspect your head,transport, and cashbox.

CLEANING

Clean the sensors with a soft,lint free cloth and a mixtureof water and mild detergentsuch as dishwashing liquid.Never use an organic sol-vent such as alcohol orthinner to clean the head.When cleaning a WBA, besure to clean the nine rollerslocated in the head. Theserollers accumulate a residuethat is made up of skin, coindust, sweat and a few othernon-identifiable products.The flathead end of a vendorscrewdriver works wondersto remove this build up. Al-ways allow the head to dryfor a few seconds prior toclosing.

ON FLOOR CALIBRATION

If you are working on a WBA,you can calibrate the head atthe game. Remember alwaysclean the sensors prior tocalibration to achieve the op-timal calibration. To cali-brate, remove the entire BVassembly from the machineand set dip switches 1-2-3-4off and 5-6-7-8 to on. The dipswitch pack is located on thetransport just below the BVhead. Replace the assemblyin the game and wait for theBV to ready up. Insert theWBA calibration paper, partnumber 057619 into thehead just as you would feeda bill. It will automaticallymove in and out of the head

TAKING BILL VALIDATORREPAIR TO THE FLOOR

By Bart Holden


until it eventually stops andthe process is complete. De-termine if the calibration wascomplete by looking at the BVready up light on the front ofthe game. The light shouldblink continuously at inter-vals of 1/10-second. If thelight blinks one to eleventimes at 1/2-second inter-vals, the game did not cali-brate successfully. Youshould remove the BV headand transport to the shop fortroubleshooting in accor-dance with the servicemanual. Return your dipswitches to the normal set-tings and try a bill. If it stillrejects you may have a prob-lem with the transport or oneof your harnesses and shouldswap accordingly with yourspares until you can rebuildthe bad parts back in theshop.

CHECKING POWER

If your game will not take inthe bill, first disconnect andreconnect your power har-ness. This will cycle the en-tire BV assembly and may fixthe problem. Once you workon BVs and become accus-tomed to them, you can listenor feel when a BV is cyclingproperly. If you still don’t hearthe BV cycle, remove the headand transport and see if youhave a bill jammed in eitherthe head or transport. Re-move any jammed bills andreturn the assembly to theslot machine. If the BV is stillnot cycling, make certain thatyour power supply harness isconnected. If it is connectedtry to replace the power sup-ply with a spare one. If thisdoesn’t fix the problem, makea note that the game needs

some serious troubleshoot-ing and move on. There’s nosense spending hours on onevalidator when you could re-pair at least ten in that time.If you hear a grinding noisewhen you first cycle a BV,check your cashbox.

Cashbox Troubleshooting

Most of the time a grindingsound simply means that thedrop team didn’t seat thecashbox properly. Remove thecashbox and check for anyloose or missing hardware. Ifyour latch peg is missing andthe threads are stripped onthe cashbox, you can rivetthe latch peg spacer to thecashbox using your rivet gunand one of the 1/8 inch rivetsyou brought along. If you haveconstant problem with yourhardware coming out apply asmall amount of Loctite toyour screws and tighten. Thisis a sure remedy and willeventually minimize the re-placing of cashbox hardwarefrom your daily routine. Next,reinstall the cashbox and lis-ten to see if this made a differ-ence. If there is still a grind-ing sound, you may have aninternal cashbox jam or afaulty cashbox. Occasionallyyou can free the jam with along screwdriver. If all elsefails, try your test cashboxand label the bad cashbox ifthis fixes the problem.

OTHER "GOOD TO KNOW"INFORMATION

If you have a bill acceptorthat cycles correctly but willnot ready up when the door isclosed, you can check thepower supply. You may havea cracked or cold solder jointon the capacitor designatedC13. A cold solder joint issimply a dull solder joint thatmay be loose around the com-ponent leg. This is a very com-mon condition on the powersupply and is easily correctedby desoldering the capacitor,cleaning the board, and ap-plying a proper solder joint.This bad solder joint on C13can also cause a game toaccumulate double creditswhen a bill is accepted. There-fore, it is a good idea to checkyour power supplies from timeto time.

Implementing a strong BV re-pair routine can make a seri-ous impact on your casino’sdrop revenue and increasethe enjoyment of yourcustomer’s visit. Keep in mindthat this floor maintenance isonly successful when coupledwith strong bench repair andcalibration. Oh yeah, onelast thing, it’s probably a goodidea to let a few differentpeople share the task of BVrepair. It has been proventhat prolonged periods of BVrepair can cause insanity andsudden fits of rage often as-sociated with violence.

- Bart [email protected]

Visit the Website atslot-techs.com


Sticking to a preventativemaintenance schedulewill enhance the perfor-

mance of your bill validators.

More than 80 percent of all thedollar bill readers that fail towork can be attributed to dirtyread heads, belts, and rollers.Contaminants, such as dust,dirt, and grime, damage theseparts. A majority of dollar billreader down time is due to dol-lar bill slippage, which is causedby contamination build-up onthe belts and rollers. Thiscauses currency slippage,which causes an incorrect read-speed ratio that leads to cur-rency rejection. It seems likethere is no way to get aroundthis, because contaminantsfrom dollar bills are depositedthroughout the reader duringthe normal use of the equip-ment.

Environmental conditions,such as airborne tobacco smokeor oil from food preparation, canalso carry contaminants intothe reader. There is, however,a simple solution. Establishinga regularly scheduled preven-tative maintenance programwill keep your equipment upand running!

A successful preventativemaintenance program includescleaning your bill validators ona regular basis, as well as fol-lowing the manufacturer’s rec-ommended service schedule.Neglecting to clean your billvalidators will cost you. Cur-rency rejection, frequent servicecalls, and premature equipmentreplacement that put your ma-chines out of business meanslost revenue and customer dis-satisfaction. Who can affordthat?

Slot Tech Feature Article Bill Validators and PreventativeMaintenance

By Jeffrey Paunicka

What kind of cleaning productsshould you use? First, youshould use a product specifi-cally designed for your equip-ment. Cleaning should also beconvenient for operators and re-peated frequently, for example,when you service your ma-chines. The most widely usedproduct approved by gamingmanufacturers to clean billvalidators is a specially de-signed cleaning cardpresaturated in an approvedmild detergent solution (AMDS).The cleaning card is simply runthrough a bill validator likeregular currency, and it is veryeffective in cleaning the readheads, belts, and rollers.

Using AMDS based cleaningcards increases the acceptabil-ity ratio in bill validators, whichcan mean less idle slot machinetime or more revenue fromITVMs (Instant Ticket VendingMachines).

Belts and rollers wear out overtime with normal use and stillneed to be replaced periodically.Over time belts may becomesmooth and/or glazed, and theywill become ineffective. Otherfactors, such as being exposedto the elements can alsoshorten the belt life.

Cautions!

Alcohol remains the best solu-tion for cleaning bill validatorsin general. However, several billvalidator manufactures in thegaming industry utilize materi-als for their optical sensors thatare sensitive to any contact withalcohol. Only use alcohol billvalidator cleaning cards afterverifying their acceptability.

Oil-based solvents?

Most manufacturers of bill

validators do not recommendlubricating belts and rollers tokeep dollar bill validators clean!In fact, lubricated belts and roll-ers attract contaminants likedirt, dust, and grime more eas-ily—like a magnet. Therefore,lubricating your equipmentmakes the belt slip, whichcauses the reader to reject cur-rency. The rejection is due tothe resulting incorrect readspeed ratio.

Bad Trade-off!

Although lubricants may ex-tend the life of belts and roll-ers, the decrease in the billvalidator’s acceptability ratio isnot worth it—and increasedplayer frustrations.

Dollar bill reader manufactur-ers strongly oppose the use ofoil-based solvents and/or ag-gressive aromatic solvents be-cause these solvents attackrubber and plastic parts, whichwill cause premature failure.

So remember, using AMDSbased cleaning cards does notreplace scheduled servicecheckups, but they will preventunnecessary downtime and ser-vice calls. The name of the gameis to make money, and stickingto a preventative maintenanceprogram based on cleaningcards presaturated with anAMDS is a safe and effectiveway to maintain your equip-ment and revenue flow.

Jeffrey Paunicka is the Presi-dent of INSIGHT3, South BendIndiana USA. He holds a degreein Chemistry from John CarrollUniversity and a Masters inBusiness Administration fromthe University of Notre Dame.The company can be reached at(800)949-0361


Slot Tech Show Report

Southern Gaming Summit

Talk about making a silk purse from a sow'sear! Anchor Gaming's SeaQuest is such apretty game, I just had to photograph it. Addanother touchscreen to the mix. - rf

Slot Tech Magazine publisher RandyFromm with former Viejas chairmanand fellow San Diegan Anthony Pico.

AC Coin's field service technicianKevin Smith paused during setup tochat with Slot Tech Magazine aboutservice issues.

R&D engineer Doug Cramer was on hand todiscuss the joys and wonders of the new,brilliant white LEDs used in AC Coin'sSLOTTO machines. Doug bent over back-wards - er, forwards to explain how some oftheir new sub-assemblies work.

Formerly of Bally Gaming, Doc Jennings isnow Service Trainer at Aristocrat Technolo-gies, Inc. I first met Doc last June during atraining mission for the United States AirForce Agency Services at Rhine-main AirBase in Frankfurt, Germany. He taught me athing or two about hopper control. - rf

Slot Techs in Mississippi will recognize thisdude. I didn't. It's Ronnie Musgrove, thegovernor of Mississippi giving the keynotespeach at the Southern Gaming Summit. Ofcourse, there was little of interest to slottechs here. I just never photographed agoverner before. -rf

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Inside Slot Tech Magazine June, 2001slot-tech.com/members/magazine/lores/june01.pdf · Inside Slot Tech Magazine ... Unlock the Mystery of Monitor Troubleshooting ... The horizontal