AES with strange video issue

[Allenbomber]

I've been struggling with an AES for a while now. When I fire it up without a cart, I get the red screen but with a little bit of garbage on the screen. It also isn't a solid red screen. It fades to green, then to black toward the top. After 5-10 seconds of operation, the garbage fades and I'm left with the same red/green/black screen. With a game in the slot, random garbage is displayed. I know my way around game repair, but haven't taken on a Neo before. I re-flowed just about every IC on the board and I can't find any broken traces, even under magnification. Anyone have a similar experience?

By the way, this is an AES3-3 board, unmodified.

 

[Xian Xi]

Probably wrong power supply.

 

[Allenbomber]

Bottom of the case says use the pro-pow adapter, it has the power regulator marked -5v on it, and I ordered an aftermarket power supply that produces 5v with a - tip. I just checked it, and that supply was producing around 5.14V with the - tip. Maybe the regulator could be bad. I'll have a look at that later. Any known test points where I should be getting given voltage before I start busting out datasheets?

 

[HeavyMachineGoob]

My AES3-3 (pro-pow AC adapter) looked like that with a 5v adapter, it's supposed to take a 9 - 12v adapter. It runs fine with a Genesis AC adapter (9v 1.2a center negative).

 

[Allenbomber]

Genesis power supply did it. Now I have a Yellow screen, so it's time to chase around a video ram error.