Sony ZN-2 PCB - swapping top board problem...

[penrhos]

I've got two faulty ZN-2 based games :Tetris TGM and a G-Net PCB.

Tetris TGM runs on the Capcom version of the ZN-2 PCB - and I get no audio out of it at all, if I feed a signal into the amp I get sound so it looks like the audio part of the PCB is dead.
The G-Net PCB is faulty, it just keeps rebooting instead of loading from the CF card, also the Bios wont update and gives an erase error and an address when you attempt to update it.

So I thought I'd try and swap the two top boards over to get one working PCB out of the two - no dice I get a blue screen with "system error and a number (which I assume tells you what the system error is).

I've gone over the PCB's with a magnifying glass and there are some differences.

1) there's a bank of resistor pads: on the Taito version it's on connection "T", on the Capcom version it's on connection "C"
2) IC652 a 20-pin dip chip is labelled CP10 on the Capcom and TT10 on the Taito and that's the only chip on the bottom board I can spot that's different between the two versions on ZN-2 PCB.
One is labelled "CAT702", "103090-00203", "9838", "0092". the other "CAT702", "103090-00203", "9749", "0084" - So I assume this is what makes the boards unique.
3) The Taito PCB is marked COH-3002T 1-665-825-11 and the Capcom one COH-3002C 1-665-825-12 so there is some subtle difference between them.

Anyone know enough about ZN-2 hardware to help me swap these over? I assume I need to change the Resistor location and swap IC652 - but what is it?

 

[jepjepjep]

In case you haven't seen this site: http://members.iinet.net.au/~lantra9jp1_nbn/gurudumps/ZNx/index.html

It seems that IC652 is the bios.

 

[Darksoft]

In case you haven't seen this site: http://members.iinet.net.au/~lantra9jp1_nbn/gurudumps/ZNx/index.html

It seems that IC652 is the bios.

I cant' see any mention on that link to IC652 being the BIOS. In any case the IC652 from both seem to be idetical the difference mentioned about 9749 vs 9838 is the production date (week 49 year 1997 and week 38 year 199.

On the other side swapping them like penrhos did will probably won't work as the ZN2 uses different audio chips. I think you'd better try with another GNET / ZN2 to narrow down where the problem is coming from.

 

[penrhos]

On the PCB's I have IC652 had a CP10 sticker on. What I don't understand is according to GURU's page TGM should have a CP11 protection chip with BIOS COH-3002C the PCB I have has CP10 and BIOS COH-3002C.


So the plot thickens...

On The Taito PCB do I need to swap IC652 for a CP10 and swap the bios chip at IC353 for one with COH-3002C in (which is a M34002C-60) and move the resistor from T to C?

 

[Darksoft]

On The Taito PCB do I need to swap IC652 for a CP10 and swap the bios chip at IC353 for one with COH-3002C in (which is a M34002C-60) and move the resistor from T to C?

That would probably clarify things. However notice that the ZN2 PCB has extra Audio ICs like kabuki and Capcom Qsound, so the combination that would work would be using the bottom board of zn2 with top board of GNET.

 

[penrhos]

I think I've made some progress.

There are two protection chips on ZN-2 games.

The base board has a custom BIOS at IC353 - so I'll need to swap that over or program one up.
The base board has a protection chip at IC652 - for Capcom PCB's it's a CP10, for Taito ones it's a TT10.
The daughter board has another protection chip for TGM it's CP11, and G-Net is TT16.

I'm still cross checking all the IC's on the base board for any other differences but so far it looks good (plus I've spotted some leaky caps on the audio side of the Capcom PCB so I'm going to swap those out).

But it looks like if I had another ZN-2 with CP10 AND COH-3002C installed I could swap the TGM daughter board over and it'd work so I need to find anything in the list below to test it.

Rival Schools (*) CP06
Plasma Sword / Star Gladiator 2 (*) CP07
Street Fighter EX 2 (*) CP08
Tech Romancer / Kikaioh CP09
Tetris The Grand Master CP11
Street Fighter EX 2 Plus CP12
Strider 2 / S.Hiryu 2 (*) CP13

 

[Darksoft]

I think I've made some progress.

There are two protection chips on ZN-2 games.

The base board has a custom BIOS at IC353 - so I'll need to swap that over or program one up.
The base board has a protection chip at IC652 - for Capcom PCB's it's a CP10, for Taito ones it's a TT10.
The daughter board has another protection chip for TGM it's CP11, and G-Net is TT16.

I'm still cross checking all the IC's on the base board for any other differences but so far it looks good (plus I've spotted some leaky caps on the audio side of the Capcom PCB so I'm going to swap those out).

But it looks like if I had another ZN-2 with CP10 AND COH-3002C installed I could swap the TGM daughter board over and it'd work so I need to find anything in the list below to test it.

Rival Schools (*) CP06
Plasma Sword / Star Gladiator 2 (*) CP07
Street Fighter EX 2 (*) CP08
Tech Romancer / Kikaioh CP09
Tetris The Grand Master CP11
Street Fighter EX 2 Plus CP12
Strider 2 / S.Hiryu 2 (*) CP13

sounds like a plan

 

[Gakman]

I think I've made some progress.

There are two protection chips on ZN-2 games.

The base board has a custom BIOS at IC353 - so I'll need to swap that over or program one up.
The base board has a protection chip at IC652 - for Capcom PCB's it's a CP10, for Taito ones it's a TT10.
The daughter board has another protection chip for TGM it's CP11, and G-Net is TT16.

I'm still cross checking all the IC's on the base board for any other differences but so far it looks good (plus I've spotted some leaky caps on the audio side of the Capcom PCB so I'm going to swap those out).

But it looks like if I had another ZN-2 with CP10 AND COH-3002C installed I could swap the TGM daughter board over and it'd work so I need to find anything in the list below to test it.

Rival Schools (*) CP06
Plasma Sword / Star Gladiator 2 (*) CP07
Street Fighter EX 2 (*) CP08
Tech Romancer / Kikaioh CP09
Tetris The Grand Master CP11
Street Fighter EX 2 Plus CP12
Strider 2 / S.Hiryu 2 (*) CP13

I have a Rival Schools PCB.
Do you want I check something on it?

 

[penrhos]

If you remove the daughter board there should be a bios sticker on the bottom board - it should read COH-3002C and the two large square custom chips should be CXD8661R and CXD8654Q

Someone is going to try the TGM PCB on his SF-EX2 and let me know how he gets on.

On the plus side I found 4 caps on the audio section of the PCB which came up as faulty on my tester, I replaced them and I now have sound on the original PCB.

I'd forgotten how hard this version is...

 

[nem]

Someone is going to try the TGM PCB on his SF-EX2 and let me know how he gets on.

I'm not someone, but it will work just fine. I have Tech Romancer, Rival School, SFEX2+ and TGM running on the same motherboard.

 

[penrhos]

I have had it confirmed that the spare TGM daughter board worked fine on another Capcom zn-2 Base board so I'm back to cross referencing the taito one to check the differences.