Well.  Our HP 3550 Laserjet came with a 50.9 fuser error. I looked it up and HP recommends to remove the fuser and reseat. Then turn on. Did this several times and no go. Still comes with this error.

Sent in the Laserjet to get fixed. Quick service, less then 24 hours to fix. But at a cost of $311.oo to get a new fuser and installation. The printer prints very quick and very nice. But the only drawback is the cost of repairs. Suppose you could also count the initial cost of the unit.  But we are back in business.