I also have a theoretically "working" City Connection PCB, and last time I tested it (last year), it didn't work and I didn't take it further. So you are not alone and I am interested.
I'd guess your caps are probably fine if you changed them 8 years ago and minimal use. However, as seasons change from hot to cold, PCB components can go through thermal expansion and contraction, becoming loose. Seated ROMs etc. can become unseated, so make sure they are in firmly and connections sound. Rust is a real problem too, corrosion on parts and traces, especially in a humid climate, even if you keep your PCBs "dry" otherwise.
It won't hurt to buy/try a new PSU, they are like $10 give or take, nice to have a couple handy, to ensure that is not an issue.
DISCLAIMER: While I have soldering/troubleshooting skills, not much direct experience in game PCB repair. Mostly my modest collection of PCBs live in bubble-wrap for 10 years at a time, and I play the game on MAME.