HP Laser Printer 50 Service Error

This error is common for all laser printers and in most cases, caused by the fuser. A 50 service tells you that the printer did not reach operating temperature in a specified amount of time. The older printers use a halogen lamp & teflon rollers with a thermistor to sense roller temp, and a thermoswitch that pops open as a one time fuse if it overheats. The newer style fusers use an instant-on heating element covered by a teflon sleeve.

All fusers run off the 110v ac power from the wall outlet. This comes from the low voltage power supply ( LVPS ) which turns on/off power to the fuser as needed  to heat the lamps or heating element. If your printer displays a 50 service error or fuser fail error code you can test it with an ohm meter. Checking the HP fuser

The 50 Service low down:

LaserJet II/IID/III/IIID ***The ac power supply is most likely bad, test the fuser lamp it's probably OK. There are two versions of power supplies. One that runs the fan with the printer on and one that only runs the fan when printing. If the fan dies you will NOT get an error which can then take out the power supply and/or the fuser. Test the fuer lamp and thermoswitch for opens if it reads good replace the ac power supply.***

LaserJet IIP ***Bad Lamp***

LaserJet 3Si/4Si ***Most likely the fuser, but could be the AC power supply. Hope it's the fuser not the power supply because you will have to tear down the printer pretty far to replace the power supply. 50 Service errors are not vary common with these printers.***

LaserJet 4/4+/5 ***Most likely bad lamp, possibly open thermoswitch, not likely but could be LVPS or DC control board.***

LaserJet 4L /5L/6L ***showing service error with all 4 LED's on, press and hold the front panel button for the error code if top and bottom LED's are on the heating element is probably open.***

LaserJet 4V ***If it is intermittent or can be cleared by shutting it off to let it cool. The fuser is running too hot, order rebuilt.***

LaserJet 5Si/8000/4000/4050 *** Power off, Remove and re-install fuser, if continues order rebuilt.***

LaserJet 8100/8150***50 is bad fuser, 50.1 check fuser but most likely bad LVPS part# RG5-4357***

LaserJet 5P/6P ***Uses primary and secondary error codes. A fuser fail is indicated by top Led ON in both primary and secondary states. To see the secondary error press "GO" and "Reset".

 

Notes to remember!!

  • The low voltage power supply is what the takes the 110v ac from the outlet and is for this reason often mistaken as the high voltage power supply. The high voltage power supply HVPS main purpose is to charge the toner cartridge with a much higher dc voltage.

  • Always Remove Power from the printer before working on it!

  • Lamps can break in shipping or if the fuser is dropped.

  • The fusers use floating connectors don't force them in.