Here is something that may work out for you. My Q800 and IIfx became randomly flaky (both of these use tantalum caps). It turns out that the electrical contacts on the motherboard to the RAM and Nubus cards were dirty. I bought a can of Electronic Contact Cleaner at an auto parts store, sprayed all the connections, and boom no more random crashes or glitches. The tin pins on the RAM slots seem to be temperamental.

Ensure that the can you pick is plastic safe.

(The specific can I used was NAPA CRC QD Electronic Cleaner)

Be careful not to spray your hand - it stings. Even if dirt on contacts is not the issue, it doesn't hurt to clean them.