Noob needs help


Twinkle Star Sprite
Hi guys, I have an AES which i have had problems with now for a long time. So here is the story. I bought It second hand and when i fired it up for the first time all I got was messed up graphics.

So I decided to attempt to install a diag bios, by removing the old one and putting a socket on it. Well I fudged it up in a big way and left myself with a very damaged board. I since rewired all the missing connection and finally got it working again in the state of the above video. I was then stuck and didnt know what else to try, the diag bios tested and came back all OK, i had tested the pallet ram connections and all was connected. The only thing I didn't have was another game just in case it could have been that.

Unfortunately life got in the way and I couldn't afford to buy another game to test it, so I put the neogeo into storage. 3 years later I was re stumbled upon the Console and was in a better position to now be able to purchase another game and try again to restore this console. but this wasn't to be as now the thing will not power on. The board revision is 3-4 and is a pro-pal (5v3a or 9v3a). When I power it I get the watchdog clicking noise and black screen, I have traced and checked all bios connections using and all is present and correct. Please im now again stuck and really want to get this working again.


Twinkle Star Sprite
Hi thanks for the reply, its a slow click, and rarely I get the garbled squares, again very rarely.
Last edited:


B. Jenet's Firstmate
"A slow click (1Hz or less) can mean that some step of the system self-test causes a crash. Address lines, dead memory, shorted traces" so it looks like you're gonna be probing that board a bit more... I personally would start with the ram, make sure they're getting 5v and then test to see if there's activity on the pins.

Xian Xi

The video is showing an obvious C-rom data issue. When the NEO GEO boot screen comes up, the NEOGEO is drawn from the C-Roms, the SNK is drawn from the S1. If the NEOGEO is missing, it's a C-rom data issue.

First, make sure you test with more than 1 game in case that game itself is the problem. Clean the slot good with contact cleaner and thick cardboard. Then clean the cart's contacts and then try again.


Twinkle Star Sprite
Thanks for your replies, here is an update,

@DaisyAge I have tested the fast ram and have data on the pins and is getting 5v. I have tested all IC's on the board and they are all getting 5v. the bios is also showing data. I have yet again checked all wiring and traces and cant find any broken traces or shorts. I'm not sure but I think this is going to be a short/broken trace I just cant find it. Just to check I have also tested the crystals and both are out putting the correct MHz.

@Xian Xi Thanks, this is why I had to wait till I could afford another game, which I have now bought. But now the neogeo doesn't power on and has the slow click of death. I'm really struggling to find the source of the problem. It was working as per the above Video before I put it into storage, but when I took it back out to re try to fix it, no power and slow clicking.

I'm really stuck now on what to do next. I really don't want to give up on this machine but it looks like its heading in that direction as I really don't know what I'm doing.