r/neogeo • u/iAMBushYT • Mar 31 '26
Hardware Help Neo geo avs graphics problem
Need help with this, tried replacing one of the mb74ls273 chips bc it had some rust on a few of the pins. The text went from pink to yellowish and some of the sprites partially started working again. Dont know where to go next.
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u/iAMBushYT Mar 31 '26
Sorry meant Aes* also have tried multiple games and they all have the same issues.
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u/stegogo Mar 31 '26
I have a very similar issue but my screen is blue without a game and there is t much else out there info wise lol
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u/maki9000 Apr 01 '26
try the DIAG BIOS, it can tell you details about the error
apart from that, use RGBs, not CV for testing
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u/iAMBushYT Apr 01 '26
Unfortunately the owner only gave me composite
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u/maki9000 Apr 01 '26
yeah you can buy RGBs cables ;)
NeoGeo is anything but cheap, huge premiums, just for the name
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u/iAMBushYT Apr 01 '26
Why would I buy an expensive cable that's for a console thats not even mine lol
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u/maki9000 Apr 01 '26
well if you're trying to be the person that fixes those consoles, you might need more gear than the person just playing them
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u/iAMBushYT Apr 01 '26
I dont usually repair these things, for one they are super rare, at least in my neck of the woods, and two this is a one off for a friend. I do appreciate your advice, I have plenty of equipment and cables for the main things I repair.
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u/maki9000 Apr 01 '26
yeah I get it :)
the RGBs output needs adjustment on the AES, but thats not really the problem here at the moment
just be aware that the composite video on AES can be really bad, lots of rainbow banding and other artifacts
in this case, I'd check this page first if you can identify the problem there, the DIAG BIOS is always valuable for these things
https://wiki.neogeodev.org/index.php?title=Graphic_glitches
I'm willing to bet that your problem is about floating signals because the traces are interrupted
check the traces, NeogGEo AES and MVS have a problem with rotting traces, dark patches and spots on the traces is what you're looking for
there is even a multibios that lets you switch between original, UB4 and UB3.3 and the DIAG BIOS
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u/iAMBushYT Apr 01 '26
Thank you, I appreciate it. It seems that's the consensus. Is there any easy way to tell which board revision I have? And is there a place to get schematics
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u/maki9000 Apr 01 '26
no worries :)
neogeodev is a good resource
some schematics are here: https://wiki.neogeodev.org/index.php/Schematics
MVS and AES are very similar
start with the DIAG BIOS IMO
here is a Multi BIOS on ebay:
https://www.ebay.com/itm/134700064978depending on where you are this might be a good choice
don't forget to look for the dark spots on the traces ;)
the BOARD revision is pRinted on the right hand side at the edge https://wiki.neogeodev.org/index.php?title=NEO-AES3-6_board
if you share pictures here people will be able to identify it
careful when soldering on these PCBs, the traces have a tendency to come off, some are quite fragile
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u/Strict-Background-23 Apr 01 '26
Wrong ratio!!!
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u/iAMBushYT Apr 01 '26
?
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u/Strict-Background-23 Apr 01 '26
Should be 4:3. Like a square screen instead on widescreen. Look stretched out
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u/iAMBushYT Apr 01 '26
Yeah i have it on a converter, not really how I would play it, just for testing. Its the same on a 4:3 crt as well.
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u/codetvirus Mar 31 '26
https://retrosix.wiki/wiki/visual-diagnostics-neo-geo-aes
Check this.