Neo Geos are very well known for having problems like this when traces are cut or the battery leaks. First step, strip the system down and see if you can see the battery, then check if it looks like it's leaking.
If it is, then you need to neutralize the battery leakage and clean it off. You'll most likely have damaged traces which unless you're pretty good with a soldering iron, it's best to find someone who can/will help you.
If it's not leaking then check the board to see for any scratches, cut green traces or otherwise chips and components that look damaged.
Either way it looks very much like cut traces so it won't be easily repairable since you'd have to hunt down the cut connections, strip back the protective covering on the traces and reconnect/rewire them. The process can be fairly time consuming and difficult depending on the conditions.
On a quest for Digital 573 and Dancing Stage EuroMix 2