It's not actually my methodology. What I described is what a DriveSavers technician told me is their approach. I agree that if they were to see something obviously damaged on the logic board, they'd likely alter their strategy. However, disassembling in a clean room does not involve much overhead for them, so that's actually not as big a consideration as one might think. Their approach is modeled on the Hippocratic oath: First, do no harm. So they do not apply power until they are reasonably certain that doing so will not make things worse.