Hello,
Some questions for you. But first, the Performa 200 is the same as the Classic II so you might also find more info searching for that model.
Have you opened the case to see the condition of the main logic board? This era of Mac is well knows for leaking caps and even worse, the possibility of being battery bombed, meaning the PRAM battery may have started to leak on the logic board causing components to fail end even worse, traces to rust away.
Do you have any high quality photos you can share of the logic board, to see if multiple eyes can spot any possible issues?
Lastly, and I personally don't care but you might find more direct help if you can somehow move this into the Compact Mac section of the forum as your Performa 200 falls under that category.
Keep us posted and hopefully we can find your issue and bring the Mac back to its original glory.