SnoopDos might be a useful tool to try Don. Set the prog to run @ startup & write a log to a safe area on another drive to read later. Sorry REM-ing the EasyNet assigns didn't fix things. SnoopDos will run in the background during install scripts iirc. You would then have had a Log of what was going on @ the time of corruption.
Interesting you remark of a yellow flashed screen earlier. Yes, it can be indicative of CPU issues. First thing to check is pull the front panel & the 5.25"/Floppy bracket & get your eye down to the CPU card/Mobo interface connector. Look @ the lines cast in the connections facings & be sure it's pressed fully home. You can jam your right finger tips between Chassis & underside edge of mobo to support it, while you push down on the edge of the CPU cards connector. Try not to spike yourself in the process.
One other thing here as well, these cards use BGA sockets which are now entering an era of failure due to age.
Back up your SCSI Boot drive user-startup & CD0 icon & perhaps try a fresh install of 3.9 to see if she behaves. Tbh, I'd do a 3.1 install, then whack the 060 Libs on there & run SysInfo or something to stress it a bit.
Good luck fella.