Champion Wrestler - Not working

[746169746f]

Hello,

I've started some restoration work on a Champion Wrestler PCB, outside of a little of bit of dust and some missing components, the PCB is in good cosmetic condition

One of the electrolytic caps wasn't looking happy so I replaced it:

One of the Ceramic caps (C26) is broken in half and I can't read its value anymore:

I scouted Google and a number of specialised sites (including this great community) but I can't find a schematic to check the value of the cap.

Would anyone with a Champion Wrestler board be able to check what C26 is? Or know where I could get schematics.

The board powers up but is currently displaying a black screen but it does output a signal. There is probably more to it than just the missing cap but I'd like to replace it before looking at anything else.

Thanks for your help

 

[jonhughes]

Think you’re missing a Crystal at position X1 in your last photo. You won’t get any display without one of those to time the CPU.

 

[746169746f]

Think you’re missing a Crystal at position X1 in your last photo. You won’t get any display without one of those to time the CPU.

Thank you for your help, I agree but here is where the plot thickens:

I found pictures of the same game board with some component differences, one board with and one without the crystal at position X1. But the one without seems to be working fine according to the 2nd picture:

I'm quite confused

746169746f2022-10-06 20:44:18

 

[Ace`]

That crystal is in the sound section, it'll work without it but you'll be missing some sounds. TMNT uses the same type of crystal and has the same issue as they're easily knocked off.

It'll work fine without the bypass cap too, it's just a 104 100nf disc capacitor.

 

[TheDaddy]

As Jon said It needs the crystal but this wont stop it working as this is for the audio and not the CPU , Have you got a scope or a logic probe ?? I would be checking the roms first and testing to make sure there is a pulse.

Dave.

P.S Me and ace posted at same time ! lol

TheDaddy2022-10-06 20:55:49

 

[746169746f]

Thanks very much for your help TheDaddy and Ace.

Here is what I've done tonight:

- I've changed the 100nf disc capacitor (for good measure)

- Checked the PROMS with a logic probe, all pins responded

- Checked the EPROMS with a logic probe and not all pins were giving a pulse

- Removed the EPROMS and dump them with my MiniPro and compared against 2 different romsets I found for the game.

- One EPROM was empty

and the 2 others didn't match 100% with either romsets.

- Burned all 3 EPROMS from one of the romsets

- Board is still unresponsive

It's giving me an input signal still and switches my upscaler on but nothing else happens, just a black screen no sound.

I'll give the board a look around with the logic probe over the weekend and report back, and maybe I'll try another romset. I used some 271001 EPROMs instead of 27C010 but that shouldn't matter.

Out of interest where could I find a replacement crystal/what type are they?

Thanks all for taking the time to read and comment

746169746f2022-10-07 00:40:41

 

[aussiekanga]

If IC42 is damsged then it will cause the whole game to lock up, Check for any pins on each taito custom for loose legs first but if none to be found my bet that chip is blown, You can remove it and the game will power up but will go into a test memu and do nothing more

 

[746169746f]

If IC42 is damsged then it will cause the whole game to lock up, Check for any pins on each taito custom for loose legs first but if none to be found my bet that chip is blown, You can remove it and the game will power up but will go into a test memu and do nothing more

Thanks very much for your message, I will have a look at this chip, it's not the only Taito PCB I have with that sort of symptoms, unfortunately.

 

[Ace`]

I used some 271001 EPROMs instead of 27C010 but that shouldn't matter

It might https://www.jammarcade.net/1mbit-eprom-confusion-jedec-vs-non-jedec/

 

[746169746f]

I used some 271001 EPROMs instead of 27C010 but that shouldn't matter

It might https://www.jammarcade.net/1mbit-eprom-confusion-jedec-vs-non-jedec/

Thanks Ace for pointing this out, I checked mine are ST M27C1001 chips and according to the datasheet pinouts they are indeed JEDEC.

746169746f2022-10-07 12:13:34

 

[TheDaddy]

You can make a simple reader for these , I made one a while ago.

Very simple 10 minute job :-

Diagram -

Mine -

Not a "Top Job" but works well enough for me !

Dave.

TheDaddy2022-10-07 12:47:42

 

[746169746f]

I did some investigation with the logic probe, I found a few things:

- Pin 6 on each Z84 which I believe is the reset line alternate between hi and lo

- Pin 8 on the TCO220IOC I believe sends the hi and lo state to one of the Z84 perhaps both.

Looking at the Night Striker schematic, although the TCO220IOC package is different the pinout seems to match with the version of the chip that I have: https://arcarc.xmission.com/PDF_Arcade_Manuals_and_Schematics/Night_Striker_Schematics.pdf

Pin 8 is indeed the reset out.

I'll do more digging over the weekend and report back.

746169746f2022-10-08 00:20:43