I've got an error screen on my Galaga 88 PCB

Shawn1976

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Donor 10 years: 2016-2025
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Hello all.
I've got a Galaga 88 PCB and I powered it up and this is what it reads on the screen.
The screen is black with the text:

Key Custom Error
0A7C
21DS
E200
0000


Can anyone give me direction as to where on the board I should be looking for this problem.
Any help would be greatly appreciated.
Thanks
 
Look on the rom board for the word Custom (towards the bottom) and try and reseat that chip...if that doesnt work, then contact jrok and get a set of roms that don't need it.
 
Any idea of were exactly the customs chips might be at on the board?

Look on the rom board for the word Custom (towards the bottom) and try and reseat that chip...if that doesnt work, then contact jrok and get a set of roms that don't need it.
 
To my knowledge no, but to be honest I'm not sure.
I purchased the board from someone here on the board and they sold the board as a Galaga 88 with issues.
That's all I really know about the board other than powering it up and seeing the error message.

Was this a rom swap?
 
It's one chip, the board has text screened onto it that says custom. It's socketed.

Yup, bottom left of the board location 10-F with "CUSTOM" screened above it.

OP make sure it's not missing (!) If it is, or it's the wrong lock-ic, then you'll need the two program ROMs PRG6 & PRG7 replaced with the images from this thread.

http://forums.arcade-museum.com/showpost.php?p=638922

- James
 
Last edited:
Ok.
In the 10F bay there is a rom with: 153 Japan / 8751Z02 written on the rom.
I don't see anything on the rom mentioning "custom" on it.
 
Last edited:
In the 10F bay there is a rom with: 153 Japan / 8751Z02 written on the rom.

The "custom 153" is the correct chip according to page 6 of the manual.
It could be a bad custom or another problem with the lock IC not being accessed.

- James
 
So it sounds like I need to replace the custom rom, yes?

Well, you can't replace the custom IC directly, but you replace the two program ROMs which skip the checks and implement the custom IC's divide function in software.

It could be a bad custom OR there's another hardware fault with the board that the custom IC isn't being read correctly.

- James
 
Bumping this... I have Shawn's problem child PCB now...
 
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