Thanks for your comment, I had no idea. Out of curiosity, do you know if it's dangerous or otherwise unadvisable to try and start it before making this modification?
It did in fact start back up again, but to what extent I don't know because it seems the power supply to the flat panel I have is fried. The O2 did play the guitar sound when starting though, and boy did it stir up memories!
The fan is also a lot louder than I remember. Thanks for the tips sir, I'll try to get the screens running to see if I can find any fun data on the drive.
The O2 shouldn't need a PSU capacitor replacement yet.
If you want to give the SCSI disk a better chance, place it flat on a table and rotate rapidly, then stop. You should feel the spindle spin.
Hardware of this era is still quite reliable so I don't think you will have problems.