channelmaniac

Check grounds on those caps that are grounded on one side and see if you pulled out any plated thru holes leaving a floating cap. Also...

Neo Geo caps don't leak. That board has been wet.

Battery leaked and ate the control traces to the Backup RAM.

I'd chalk that up to a UniBIOS 4.0 glitch. As for the battery damage traces, check the pins on the connector. Do you have continuity...

If the ZMC2 is working, don't touch it. Clean up the area the best you can to degrease it and get the corrosive oils off that leaked out...

Yeah, you'll only have Left audio and miss all the sounds and music from the right channel. You can get an adapter to plug a stereo...

I recommend to my customers to stop at 3.x UniBIOS. Check continuity between the top and bottom boards through that connector by the...

Check a few traces... Make sure the vias are good and continuity is good to the bottom side of the PCB.

Not needed... Clean the slots and take a close look at the connector next to the battery. If it has green gunk on the pins you'll need...

The M1 ROM is the Sound Program ROM. Without it you have no sound. You have corroded connectors/traces on that edge connector that lead...

Pic of the battery and ZMC2 area?