Well the signs will be tell tale. You will flip it on one day and it will just go click,click,click and not power up. even the dana variant has cap issues now.

The first thing that will go on the LC475/Q605/575/and performa variants, its usually sad mac if you have an ethernet card installed. Seems like those 100uf 6.3v caps right by the PDS slot are the first to go.

Or the sound will become really quiet. IF the caps get really bad the main board will just not boot at all, no video.