"Where can I find the meaning of the flashing error codes on a Laserwriter II NT printer? It is flashing both the paper jam and the paper out light. The fuser doesn't heat up."
(From: Ralph Wade Phillips (email@example.com).)
It means that the fuser isn't getting to proper heat. This might be a blown fuser, might be a bad AC Input Block, might be a bad DC controller.
Before I fought TOO hard, I would pull the fuser assembly and check the 115 VAC inputs for continuity. If you don't have any, then I'd say you most likely have an open fuser lamp, and it will need to be replaced.
If you have continuity, I'd change out the AC Input Block, and work from there.
The DC controller being dead is rare, but it CAN cause the same symptoms.
(From: Mark Wolfe (firstname.lastname@example.org).)
Do what the other guy said, but instead of replacing the AC Power Block, check the triac at Q101 inside the ac power block. Common failure on this engine. When you do fix it, put a good heat sink on the thing.