WMS 400 - "COINJ" Error

[Billythekid]

Hello,

So I'm getting an error "CoinJ" I isolated the problem to the coin optics board. When it is disconnected the machine plays ok with bills...
Are there any suggestions for fixing it?

Steve

[kenokarz]

you need to replace the optics board, this will take care of the problem, call joey see if he has one,

[Billythekid]

Update: I replaced a bad transistor and it's fixed!!  .39 part and 15 minutes to put in and reassemble. It was the transistor that is associated with the transmit IR LEDs.

[cfh]

what transistor and on what board did you replace?

[tacman]

Billy, please posts pics as it would help others in the future or possibly present! 

 Dan (tacman)

[KirkLasVegas]

Good show Billy!
best to keep a few 2N2222 and 2N3904's in stock for that reason
I use a "Velleman" portable scope like this one for working on Pins and Slots.
Makes troubleshooting easy. They are pretty cheap,under $200 for a 10Mhz model

Kirk in Vegas

[Billythekid]

Ok here is a picture of the part that went bad on my Williams coin optic board. There are three transistors on this board. 1 controls the upper IR receivers (2), and the second controls the lower IR recievers (2) - these two transistors are the same part (2N6427), The third transistors controls the (4) IR emitters on the daughter board part number 2N3904N. That is the only one I replaced but at .39 cents each you could do all 3, they only had the one I needed so I only replaced that one. I also hit all the solder joints with heat incase there were any cold solder joints. The emitter side board is very warm so with it going hot cold hot cold when turning the game on and off it had the potential for a bad solder connection.

And it's fixed!!!

[KirkLasVegas]

Good tech there Billy
A simple way to "See" if they are working, is to use a black & white video camera and observe them! B&W cameras can see the IR energy just fine. To see if your camera is sensitive, look at the end of your remote control for the TV set. You will see flashes of light from it.

The "2N6427" is a NPN Darlington, or actually TWO transistors in one package.The first one is a amplifier, the second is a switch.They will take a small signal and drive or control power hungry IR LEDS,Coils,Relays where a 2N2222 or 2N3904 just isnt up to the job

Hope this helps 

Kirk

[cfh]

you can use a regular digital camera to see the optic infrareds too.
sometimes you can use a flashlight to simulate the transmitters,
and test the receivers. but on slots they do pulsing of the LEDs
to prevent this. works on pinballs though, but i'm pretty sure
it doesn't work on slots. with the door open and game on it's
sort of in test mode, and would be easy to try.

[tacman]

Thanks for the picture, Billy!  K+ for the problem solving!

 Dann (tacman)

[KirkLasVegas]

This is my "IR Tester"....
A Zenit "NightScope" usually used to find people/animals in total darkness, it shows IR sources VERY well 

[karloz370]

hello this is the problem I have noticed I have replaced all the transisters and hooked up unit back up and still get the CoinJ error unsure what else can be ? The problem before this was that the powersupply top and bottom went out so now I have rewired a atx power supply to fix that problem have'nt noticed any problems with that as of yet just need to get the CoinJ error to complete in order to be able to put nickles into the machine thxs.... 

I am thinking maybe I need to buy another used Williams coin optic board if you know where to buy let me know 

[kenokarz]

thats what you need to do

[cfh]

the problem is often the optos themselves. i have *never* had
to change the opto transistors, as stated above. I have had to
change the opto transmitters though. they are essentially little
flashlights, and are on all the times while the game is powered on.
they do wear out. i don't have a part number replacement unfortunately,
but i suspect them are the same as pinball IR opto transmitters.