The ceramic heating element and everything else looks fine. I knew the fuser was the cause of the error, and the parts were not cheap so I carefully disassembled the fuser to see if I could isolate the exact part that was broken.
#HP LASERJET 1536DNF MFP SCANNER MISFEED MANUAL#
The service manual indicated some ohms testing to be done on the problem fuser and all results came back showing all the correct readings. Since I am not made of money I figured I could rebuild a fuser just as well as anyone else so I went on a search for the parts, but it was like calling Area 51 and asking what they were hiding. I swapped the fusers back again and the error returned, pretty much proving the problem is in the fuser. I swapped fuser with the one in my other identical working printer and the fuser error went away. After checking the Internet I determined it might have broken the ceramic heating element. A few weeks ago I had a massive paper jam in the fuser and a day later got a Fuser Error 50.1.
Shortly after that I replaced the fuser with a genuine OEM HP fuser and it fused great for nearly a year. I replace a bad DC controller board in this particular printer about a year ago. Until recently I had two HP 5000 LaserJets and was able to trouble shoot by swapping parts. The previous fuser on my LaserJet 5000 lasted over 7 years and while I was not getting any error codes, it was not fusing laser plates as well as I liked. I am not a tech, but I have been repairing my own cars, printing presses, computers, printers and anything else that breaks for over 35 years. I have a HP LaserJet 5000 with a Fuser Error code 50.1, meaning low temp. SOURCE: 50.1 fuser error on HP 8150 LaserJet Printer