Bally V2336 Video Poker

[techknight]

I found one of these machines for $40 bucks but the problem is, theres 2 bundles of wires, with 4 plugs total that were unhooked. well 2 of them went into the mainboard, and the other 2 i have no idea where they go.

so anyway, i tried to power the machine up, and the video was corrupted, and the buttons didnt wrok, coins werent being picked up, no sounds, nothing. totally dead.but there was a picture, however it looked like an old DOS game that crashed.
gray bitmap with random pixles, and upside down letters and some right side up letters that were littered across the screen. I'm assuming this is becuase its rendering what the "undefined" state of the bits in the display RAM. So the MPU isnt working.

I pulled the system boards, and noticed that the battery had corroded a 74LS133 chip nearly to peices. i removed the chip, and cleaning the board. i guess i will replace this chip and see what happens. i dunno. plus i might need to look at the power supply also. it might be good, bad, ugly, dunno.

Does anyone have a wiring diagram? schematic? or something? I also have an EEPROM burner, so if someone has a fresh copy of all the ROMs i could reburn all the EEPs to eliminate this as a cause.

[techknight]

I guess no one knows? hehe.

this machine is starting to annoy me, hehe. I replaced the bad 74LS133 and repaired the corrosion/circuit. One thing i noticed is the coin comparator has a red light, and it isnt even on. the connection plug has no power at all either AC or DC.

and the picture is still corrupted. everything comes up on a grayish pink background, and random pixels. sometimes youll see random club, or spade sprites in different spots, along wiht letters. it changes each time i power cycle the machine.

Also the rectifier diode on the main power board gets so hot i can melt solder on the heatsink. and I noticed my 5V supply is down to about 4.6v so something isnt right somewhere. 12V is steady. not sure what else to test. (dont have manual).

so after playing around with it a little bit, the video signal died off. so all i had was a "dark gray raster screen" left on the CRT. and my 12v dropped to about 5v, and the 5v went to 0v. all the fuses are fine. the three on teh board, and the 3 on the bottom back twist-ins. Also i pulled the system board again, and the video SRAM chips are so hot you cant hardly touch them, but you still can. Doubt this is normal. somethign is wrong and ill probably have to get a whole new board.

So i pulled out the power supply in the back, and someone took finger-nail polish and marked "BAD" on the back of the power supply board. So that explains a few things. they marked it BAD for a reason. I checked every component on the board, all the resistors, diodes, and transistors test fine. the capacitors are OK and ESR test ok. But i come back to that "overheated" 20 amp TO-3 rectifier at PR-1, one lead to case is open, the other lead to case is shorted. So that diode shorted out. probably causing the loss of 5V and the sag of 12v. dont know.

Any ideas? thanks. this is very very difficult to troubleshoot voltages without a wiring/voltage diagram. Also is it normal for the video SRAM ICs to get that HOT? the culprit IC number is 93422DC

[techknight]

oh well. either this forum doesnt get activity, or no one really knows a darned thing about these machines .

[Joeylc]

can you post a pic of the game ???

[blueridgeslots]

It is just older than most members here know about, you usually have to be smart enough to read a schematic and us rednecks are unable to hold a cold beverage and look at anything other than pictures at the same time

[techknight]

hehehehe. i guess. No i was going to try and post a pic but the batteries were dead. and the power supply blew up before the batts had enough charge to take the picture.

Once the power supply comes in and it still dont work, ill take a pic then.

[techknight]

Here is an attachment of the pictures i took of the boards. youll notice the power supply board, i removed the common anode rectifier diode that blew up. (half of it was blown already).
maybe the cause of the whole problem? I dont know. gotta wait for another power supply module to come in before ill know.

[techknight]

Ok. power supply took care of it, it seems to function.

but i got a new problem. the hopper. it doesnt function at all. so i begin to suspect the hopper control board.

pulled it, and im reading a really low voltage drop between the upper transistors from B to E. dont know. anyone have a schematic of the hopper?

[techknight]

ah well. nevermind. ill just end this monologue

[jay]

Good Post, I am someone will benefit from you sharing this information.

Not sure who might have a manual for this one.

[techknight]

I got one off ePay. it just strikes me as odd that not even one person chimed in with any knowledge or good information about this machine.

Are these machines REALLY that rare? or the people that have knowledge about these machines that rare also? I'm not trying to start a flame war, im just curious as to the reality. hehe.


Anyway: On to my further endevour: 

The button lights and tower light appears not to operate. as with a solenoid here and there. but the coin actuator, and coin drop solenoid operates. and the game plays fine now. Im still waiting on the new SCRs and TRIACs to repair the hopper control board, and hopefully bring it back to order.

Upon further looking into the main sound/control board, it appears the lights, solenoids, upon several other things are controlled by L2001L4 Triacs, which cross to a 2N6071. theres 28 of them total, as you might see in the picture.

To eliminate defective TRIACs as the cause of the dead button lights, and etc... I replaced all 28 of them. still no change in operation or gain of the lights. Of course, i didnt loose anything that i had previously either, so that means the cross traics work.

So, i guess im going to have to look further back into the latches that drive the TRIACs, a.k.a..... 74LS374 8-bit tri-state LATCH ICs. this IC is responsible for the CPU's ability to latch on which outputs to set high/low. so the CPU can de-select the address decoder for those bits, and move on. meaning the 8bits on the Q inputs of the latch would be changing states very rapidly, while everything on the D is held to whatever states were latched in at the clock.

Its possible one of these ICs are bad, so im going to have to build a home-made makeshift storage logic analyser, probably an 8 LED A channel, 8 LED B channel, and 3 trigger channels, the trigger channels would be attached to the clock/reset/output enable of the latches, and when i say trigger, every time the state changes from high, to low, to high, etc etc it would "store" the states of the A and B channel into the memory of my logic analyzer im going to build.

That way i can "thumb" through the logic analyser to see if the stored data is following the truith table of the latches, to eliminate those as suspect. But if it never triggers, meaning the latch is never called up, that means i have to look further back into the address decoder for that latch. and check here. hehe.

[tacman]

I'm surprised Foxsslots has not chimed in here on this topic. I know Barry is experienced in the Bally E & V machines in both the 1000 and 2000 series. Maybe he just didn't see this thread.

 Dan (tacman)

[FOXSSLOTS1]

sorry - I have been responding via email.  not much I could add that would be valuable info on NLG

[techknight]

ive gotten manuals and parts from barry.

I'm on my own with the rest though. hehe.

going to have to inspect the 374 series IC chips for damage, then if that checks out ok, i gotta go through the address decoders, to even see if ROM is calling them. (which im sure it is).

[techknight]

Well i got the hopper working today. hehe. repaired the damaged parts in the hopper control board, and shes up and running. hahahaha.

Well i guess everythign else works, so lights are not that important. maybe its in the dip switches? maybe not. analyzed the address decoders and the TRIAC latches, everything is good. so the CPU just isnt addressing it. could etiher be dip switches telling ROM not to, or something else.


Oh. P.s.

yea my picture looked like the same thing. except it was much worse. Turned out it was the power supply. So i fixed it. In your case, it shows that in the bottom two, its working?? but i believe your case is probably SRAM if those bottom two pics are yours also.