error message


I have a very old Hp LJ 3, I know its very old but very reliable and trying to know if it can be salvage. The error massege is 50 SERVICE. Thank you


Hello Bobby,

The 50 Service error usually means something has happened that requires a trip to a service center to be fixed. The last time that I ran into this message on a LJ 3 and again on a LJ 4si we had to have the fuser and rollers replaced. At the time the LJ 3 was under a repair contract purchase for us by another government agency. The LJ 4si was a $3,000 printer with no service contract and spending $400 to fix it was cheaper than buying another one. Depending on the age of your printer and the volume of printing you do, it might be cheaper to buy something new than to try and repair. The LJ 3 is a very good printer, we still have a couple around the office that keep on printing, but they are starting to show their age (16 years old).


This is the wrong forum for this type of question (the LJ III is not a calculator after all).

However, try the following link, they appear to be offering a "fix error 50 kit" for $69.95.

Note that I haven't tried their service, so I do not know whether their repair kits are for real.



Hi Bobby,

I recently fixed my LJ using the repair kit purchased from They shipped the kit quickly and the instructions were great. I'll certainly use them again if the need ever arises.




I agree with what Richard has experienced. We had two LJ3's at work that got the fatal 50, and ended up throwing them in the dumpster. On the other hand I had a personal one at home that got the fatal 50 and was able to recover without repair. It is now at work and runs about a ream every two weeks by my desk.

No one will ever figure out why this one recovered. It was shut off for about two weeks and then when tried for the last time before going into the dumpster, it worked. It remains on all the time now and has not been shut down except for maybe 10-minutes in the last year.



IIRC, this is a Canon SX engine. Error 50 means the fuser did not get to the correct temperature (either too hot or too cold).

Common causes include :

The fuser lamp itself, the overheating protection thermostat (check for continuity between the pins of the 2 pin plug on the end of the fuser with the fuser removed, if it's open, then one of those has failed).

The triac Q801 in the AC input block

Capacitors and diodes on the protection PCB (the upper PCB in the AC block).

Occasionally problems on the DC controller board.

[Surely you didn't think I just fixed -- and had info -- on the handhelds :-)]

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