Quoted from stefanmader:
Thank you for the fast answer. I think i will pull out the board and try cleaning everything i find like you suggested. Havent seen the crusty chip thanks, didn't even knew what to look for.
I do think its not a battery. Definitly no heatshrink. I ll take a better picture. But a cap would be ok right? It just not store credits and highscores i think.
Thank you very much, how can i clean the chip sockets? Is contact spray a good idea to use for that?
The DIP sockets can't really be cleaned. They may be ok as it looks like the black oxidation is mainly on the chips. If the sockets are bad they would need to be replaced. Those have to be done carefully otherwise pads can fall off and the traces on the board can be damaged causing more repair work. One of the boards I just fixed had a few extra hours due to prior work.
For the DIP chips I use a scotch bright pad from the top of the pin to the bottom. Again, you need to be careful here since sometimes the leads get weak and can break. That causes more work.
Some good references to Gameplan repairs:
Star Trip is a cool machine. I had one for a while but had to sell it due to lack of space,