I think these sorts of repairs are better off in those printer repair forums. Google up "fixyourownlaserprinter" or was it "fixyourownprinter"?
I have a Lexmark C522n printer that's stuck in a reboot cycle. Yes, it's old. I would just junk it and buy a new printer, but I just purchased a few hundred dollars in supplies. So, I figured it was worth a couple of tries to fix it.
Basically, it boots up. I hear a series of clicks and whirs. Then it reboots again. Same thing over and over.
First thing that jumped to mind was the power supply being overwhelmed by the heating element. So, I searched around and purchased a new high voltage power supply board. (Man, I'm in love with whoever designed this printer. It was so simple to swap out. A welcome change after the hassle of cleaning filters in laptops.)
Anyway, after replacing that, at first, I thought it didn't work. The next reboot took forever. But, when I left it plugged in and on for awhile, it finally did boot. Same thing. Endless reboots.
I'm not sure what to try next. Looking for ideas.
One thing I noticed. On the other side from the power supply, there are the ends of some part that rotates. The stickers look scorched. I don't know if that's normal. Picture here. I know that some parts of the printer get pretty hot, so maybe this is normal. But, that seems awfully close to catching that stuff on fire, so it makes me wonder.
Any help appreciated,
Drake Christensen

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic