Laserjet 4 Error Code 50 Service dilema

[RWKC]

My Lasejet 4 has an error code 50 Service that I cannot resolve. I have replaced the fuser assembly and still have the error code. Any suggestions on how to resolve this?

[cs_steve]

Technically speaking, the next thing to replace would be the printer's DC controller/power supply...however, keep in mind that it is also possible to have 2 fusers fail in a row.
Potentially you could end up replacing several parts and still not fixing the problem...

In these cases I generally recommend you just replace the printer...typically when you add in your time, the trouble it takes in taking the printer apart, and then the money you invest in repairing a printer with this non-fuser '50' problem, you can get a professionally-refurbished LaserJet 4, 4Plus, or 5 instead...

[redcow]

Remember to Power off for 30 minutes to allow the capacitor on the DC controller to fully discharge. If you don't allow this capacitor to discharge, you will still get a Error 50 even if you have fixed the problem. This may clear the error - either temporarily or permanently.

[MichaelTech]

And pull the plug! It can trickle juice to the p/s.

[olanmila]

Check this one out.

50.4 PRINTER ERROR
A problem exists with the customer’s line voltage.
1. Remove the printer from any UPS supplies, additional power supplies, or power strips.

2. Plug the printer into a wall outlet and see if this resolves the problem.

3. If the printer is already plugged into a wall outlet, try another power source in the building that is independent of the one currently being used.

4. The line voltage and current source at the printer location might need to be inspected to ensure that it meets the printer’s electrical specifications.

Hope this one helps you.

[redcow]

That's a gothcha, never plug a Laser printer into a power strip.