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Advice on fixing a system 32 golden axe2

mypinballs

mypinballs

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Hi

Got a black screen golden axe 2 board. Tried the decrypted roms idea and removing the extra security board. Made no difference unfortunately

I see pulsing on the roms addr and data but no activity on the rom board pal. Also the 27c020 roms oe line is high

Looking for advice on what to check next . Reset chip? Need type & location of it please

Hoping its not cpu failure :( :( As board itself is very clean

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With my hacked roms it should be ruling out dead battery. The game waits for a value to appear in shared ram. Hacked rom looks at rom for this string which always is there :).
Does it reset the cpu(s) when booting? Might be waiting on the Z80. Any different rom boards or mainboards to swap and rule out?
 
Asure said:
With my hacked roms it should be ruling out dead battery. The game waits for a value to appear in shared ram. Hacked rom looks at rom for this string which always is there :).
Does it reset the cpu(s) when booting? Might be waiting on the Z80. Any different rom boards or mainboards to swap and rule out?
Click to expand...
Thanks for the reply, Yeah unfortunately this is the only system32 board I have, so this is abit of a walk into the dark! Interesting tech though and great work on the decryption stuff.

I'm going to check the reset stuff shortly, was hoping for a pointer as to the chip used for reset/steady 5v etc.

I will check the z80 to. Any info out there on a summary of how the boards start up etc, chip location and usage etc.?
 
Fixed It! :)

Bad PAL at IC51..

Weirdly the pal was also causing the reset chips at (IC11 & IC12) to malfunction, but once the pal was changed they were ok again. The current draw was 3.15a with the dead pal, and dropped to 2.75 a once back up and running. Only by using a separate higher spec power supply did I find this out.

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Hi,
Just got a GA:RoDA last month and it has the same problem: Black screen.
Since It has no Suicide CPU, I concluded that the problem resides somewhere else.
After some research and this topic (Thank you mypinballs and Asure!) my guess the culprit can be the following:
- Bad Ram chip (MB8421-12L) on the Security Board (834-8529-02 board)
- Bad EPROM (M27C512, EPR-14468-02) on the Security Board (834-8529-02 board)
- Bad PAL at IC51 | Buying a replacement one and just replace it will suffice, or do I need to program it?

I will start by burning EPROMS with the Decripted roms and test the board. Thank you Asure!
What Eproms do I need to change in order to use the decripted ones?

Thank you very much!
 
Last edited:
Geadas_ said:
Hi,
Just got a GA:RoDA last month and it has the same problem: Black screen.
Since It has no Suicide CPU, I concluded that the problem resides somewhere else.
After some research and this topic (Thank you mypinballs and Asure!) my guess the culprit can be the following:
- Bad Ram chip (MB8421-12L) on the Security Board (834-8529-02 board)
- Bad EPROM (M27C512, EPR-14468-02) on the Security Board (834-8529-02 board)
- Bad PAL at IC51 | Buying a replacement one and just replace it will suffice, or do I need to program it?

I will start by burning EPROMS with the Decripted roms and test the board. Thank you Asure!
What Eproms do I need to change in order to use the decripted ones?

Thank you very much!
Click to expand...

You need to replace IC17,IC18, IC8,IC9 with the decrypted ones then you can remove the security board. The PAL at IC51 will need to be programmed if this is a program. I used an ATF16V8 chip. If you want the chips already programmed let me know

Regards

Jim
 
mypinballs said:
You need to replace IC17,IC18, IC8,IC9 with the decrypted ones then you can remove the security board. The PAL at IC51 will need to be programmed if this is a program. I used an ATF16V8 chip. If you want the chips already programmed let me know

Regards

Jim
Click to expand...

Thanks for the help. I do have a Eprom programmer.
Where can i get the file to program the PAL chip?
Do we have alternatives to the 27C020 and 27C210?

Thanks for all the help!
 
mypinballs said:
You need to replace IC17,IC18, IC8,IC9 with the decrypted ones then you can remove the security board.
Click to expand...
When looking at the roms in the ga2_nosec zip available on here IC8 has the original date of all the other roms (1996) whereas IC9, IC17 & IC18 are all 2016. There is another zip available though (from Mr Gurus site) where all 4 have the time stamp modified.

Geadas_ said:
Thanks for the help. I do have a Eprom programmer.
Where can i get the file to program the PAL chip?
Do we have alternatives to the 27C020 and 27C210?

Thanks for all the help!
Click to expand...
Here you go mate
https://wiki.pldarchive.co.uk/index...:_The_Revenge_of_Death_Adder_(SEGA_System_32)

I didn't have a 27C020 on hand and tried to double the file to use a 4 Mbit eprom but had no success, unsure if the board is defective or it's the eprom so waiting on a 27C020 now.
 
Finally received everything needed to try to fix it. AND.... nope. Still nothing.

Programed the EPROMs, programed the GAL chip, removed the security board and still no sign of life.
What am I doing wrong? Do the eprom files need to be byte swapped? Do I need a special programmer for the .jed file? I use an TL866II programer with the suplied program (XGPRO)
Here's what I did:
- Cleaned the jamma edge;
- Removed the security board;
- Programed the EPROMS with the IC17, IC9 and IC18 from the ga2_nosec.zip that I found. They're dated 2016, so I assume that I got the correct edited files.
- Programmed the GAL16V8 with the suplied jed file from the pldarchive site. Thanks tiff_lee! Used XGPRO.

Hopefully I'm missing something obvious...

cheers
 
Use all four roms, they are a set, replace them in a set. Not sure why you needed the gal, unless it was missing/broken.
 
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