asked Sep 24, 2015 at 6:56am
Hp HP LaserJet 4SI

error 50

I have a Hp LaserJet 4Si printer with an "error 50" problem.

The Laserjet IIISi&4Si service Tool reports this error : "Fixing unit malfunction : Heater open"

I have tried to clear error 50 and failed.

I have checked J1 and J11. These are Ok.

I did not find J3.

I have checked CB101 ( circuit breaker 101 ). It appears with no resistance. I am not sure it is normal for the red pin cannot be plugged in.

The fusing assemble keeps despairingly cold.

Does anyone have an idea to fix this problem ?

Most likely the quartz lamp in the fuser assy. burned out. you can remove it and check the resistance on the 2 large pins in the connector. Should be several ohms.

by moe on Sep 24, 2015 at 3:20pm Add comment

Thank you for your quick answer.

I have removed the fuser assembly and checked the resistance. It's about 6 ohms.

I have made other tests with a brand new fuser assembly before posting. Nothing has changed.

by miricard on Sep 25, 2015 at 11:48am Add comment

The next thing to try would be the AC power supply. That's what powers the fuser assy. Haven't worked on one of those old beasts in over 5 years.

by moe on Sep 26, 2015 at 10:17am Add comment
First thing would be to replace the fuser.
by dmzcompute on Sep 30, 2015 at 6:52am Add comment
Sorry did not see the other posts. New format on this site s***s.
by dmzcompute on Sep 30, 2015 at 6:54am Add comment