|PFC---Power factor correction. It's not a spec that matters as far as your computer hardware is concerned.|
Might be PSU problem but if the voltage dropped enough on on the cdrom's 5 or 12 v connections it should also affect the hard drive and maybe the motherboard--that is you'd be experiencing other problems too.
So maybe it's the cdrom which for some reason needs to be reset occasionally, which a restart would do. Still, I've never run across that problem either.
How long has it been doing this and did anything change prior to the problem starting?
Onward to 300