Neogeo AES, dead or not dead ?

dr.wily

dr.wily

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I have a Neogeo AES (mainboard model neo-aes3-4). This Neogeo work fine during several years. But today, it decide to be a bit capricious. My Neogeo don't want boot any game ! No sound, blank screen. No boot.

I looked at the mainboard, trace are OK, IC seem good, BIOS is an origianl BIOS and none modifications.

I don't want to junk this neogeo, there is too few Neogeo in the world.

Please live again yhis Neogeo.

Thank

Sorry, English is not my native language.
 
MKL

MKL

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What colour is the screen when you run the system with no cart?
 
MKL

MKL

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A solid red screen would mean a problem with the work ram (you get blue when the system is OK). It can probably be fixed but only by someone experienced. Where are you located?
 
dr.wily

dr.wily

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First, thank for your help.

I am french. You can fix this ? I am experienced in repairing video game system. but this issue is beyong my knowledge.

Work ram ? Where is located these chips ?
 
MKL

MKL

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It's the couple of surface-mount 43256 chips near the reset button. I can probably fix it.
 
MKL

MKL

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Yes, it's those chips. A visual inspection of the traces around the chips cannot guarantee their integrity though. Continuity should be tested across each leg of the chips and the corresponding leg of the CPU. Having said that, the traces on a home system are generally well-protected and therefore less likely to go bad than the chips themselves. If you installed a unibios (even a temporary, solderless installation is possible) you would get a an error message with more info about the failure. If you're going to replace the chip(s) make sure the job is done by someone who has enough experience with surface-mount stuff as a n00b will easily screw it up even more.
 
dr.wily

dr.wily

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OK, since my first post I did not manage to fix this issue on my Neo geo AES.

I am ready to ask some help to someone who can repair it. But I need son informations :

- Who ?
- Where ?
- price ?

I live in France.
 
WilalvesBR

WilalvesBR

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MKL said:
A solid red screen would mean a problem with the work ram (you get blue when the system is OK). It can probably be fixed but only by someone experienced. Where are you located?
Click to expand...
What would be the problem in a system that always end on a solid yellow screen when turned on without any cart inserted?
 
metallizer

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Blue = All tests passed (does not test z80).
Red = WorkRAM error (0x100000 region).
Green = PaletteRAM error (0x400000 region).
Yellow = VideoRAM error (programmed through custom port).
Pink = Bios selfcheck error (0xC00000 region).
Cyan = Memory card error (only tested if card in unit and blank).
 
WilalvesBR

WilalvesBR

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metallizer said:
Blue = All tests passed (does not test z80).
Red = WorkRAM error (0x100000 region).
Green = PaletteRAM error (0x400000 region).
Yellow = VideoRAM error (programmed through custom port).
Pink = Bios selfcheck error (0xC00000 region).
Cyan = Memory card error (only tested if card in unit and blank).
Click to expand...
Thanks :smirk:


Here is a video of what happens when i turn on my AES without any cart inserted.


Where are located the VideoRAM chips on a 3-5 motherboard?


Regards.
 
Last edited:
M

mmmonkey

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Hi

I've just got my hands on my first piece of Neo Geo, a faulty AES with a red screen. I had a look around the chips by the reset button and found a broken trace which I've bypassed with a piece of Kynar.

Now I get a blue screen on boot up :) It stays blue for a bit then starts blinking on and off - is this normal?

I don't have any carts yet, so can't test it fully. It's connected up via composite at the moment, until I RGB bypass it and make a RGB cable.

Anyone able to tell me if blinking blue is normal?

ta
Pete
 
channelmaniac

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If you get a click in the speaker each time the screen flickers then you are stuck in watchdog... meaning the CPU can't boot so it's getting hammered by the reset line over & over in hopes that it will start up.

Red screen = bad work RAM. That's the surface mount ram next to the CPU on the board.

I have the chips on my website and can repair your board for you if you don't know how to replace those.

RJ
 
M

mmmonkey

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Thank you for the quick reply!

There's no clicks going with the blinks. I turned the volume all the way up and also listened in on headphones. I get the click if I manually reset it but definately not when the screen blinks by itself.

And I've found out that if I hold the reset button for a second or longer and then let go of it then I get a blue screen that doesn't do anything - which I'm guessing is normal

Ta
Pete
 
Last edited:
channelmaniac

channelmaniac

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Put a game in it and see if it plays... If it does then you are in business.

There will still be a problem in the power on reset line that will need to be fixed. I'm not in the shop right now to tell you which parts to check.

RJ
 
M

mmmonkey

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Cheers again. Just waiting to get my hands on a game to give it a test, if you get a chance to have a look and tell me what to check that would be great.

Ta
Pete
 
tony starks

tony starks

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mmmonkey said:
Cheers again. Just waiting to get my hands on a game to give it a test, if you get a chance to have a look and tell me what to check that would be great.

Ta
Pete
Click to expand...

Got a spare Fatal Fury 2 Jpn Cart boxed if you want, free of charge if you ain't got any games to test your system.
 
M

mmmonkey

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Crikey, that's generous. I've just agreed to buy Fatal Fury Special off of buster_broon, Special is kind of like an update to 2 isn't it, otherwise I would have offered you some cash for it.

So I'll leave it ta.

Cheeio
Pete
 
tony starks

tony starks

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Yeah Fatal Fury Special is better than Fatal Fury 2 imo. Ok mate, well tell us what happens when you finally receive FFS.
 
M

mmmonkey

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@ channelmaniac mainly - I've sorted the Blue screen flickering. It's a bit embarrasing really - it was the front AV sockets on my old TV! I'd spent hours with this tinkering round trying to figure it out!

Hopefully when Fatal Fury Special and Super Sidekicks 2 turns up I'll be having my first go on Neo-Geo :)

Pete
 
M

mmmonkey

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Woohooo, it works! I couldn't believe it. Couldn't play a game though, the Start button on my stick wasn't registering - had to carefully remove the cover on the plug and push the contact back in place.

Too tired to play now though

Pete
 
tony starks

tony starks

Starks is always out.
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mmmonkey said:
Woohooo, it works! I couldn't believe it. Couldn't play a game though, the Start button on my stick wasn't registering - had to carefully remove the cover on the plug and push the contact back in place.

Too tired to play now though

Pete
Click to expand...

Excellent news, enjoy the experience :buttrock:
 
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