Laserjet 4p will not turn on. Is there a fuse somewhere?

[Dwf2008]

Nothing new. It just will not turn on all of a sudden. Like a blown fuse or no power.

[sandytechy20]

@Dwf2008

This is a great location to get assistance! I read your post and see that you are getting print quality issue on HP LaserJet 4p Printer. I would like to help you resolve this issue.

Perform a hard reset on the printer.

1. Make sure that the cartridge is genuine HP cartridges.

2. Make sure that the cartridge is installed correctly.

3. Print with a different cartridge.

4. Check the paper type in the paper tray and adjust the printer settings to match. If necessary, select a lighter paper type.

5. If the problem persists, go to support.hp.com.

Click here and refer the document to perform the above steps.

Let me know if that helps.

Cheers.

[Dwf2008]

Geesh Sandy, did you even read the original post?

[sandytechy20]

@Dwf2008

Thanks for the reply.

I understand the issue better now.

Perform a Hard Reset on the printer.

• Remove the power cable from the printer when it is turned on.
• Press and hold the power button for 60secs.
• Connect the power cable to printer and directly to wall outlet.
• Turn on the printer.

Try with the different power cable if you have.

Connect the printer to the known good outlet.

Let me know if that helps.

Cheers.

[Dwf2008]

The on/off switch is a mechanical rocker switch, not something you can press and hold.

[sandytechy20]

@Dwf2008

Thanks for the reply.

I appreciate your time and Patience,

I request you to contact HP Phone Support for further assistance on this.

Cheers.

[davidzuts]

Sorry to say but Sandy is typical of the support you receive from hp these days. He really has no idea about your printer and to be honest he was probably not even born when your printer was introduced. To be honest most times when a printer this age no longer powers on, the issue is the combination engine control board/power supply which has failed. In the many I have seen over the years the fuse is almost never blown and if you find one with the fuse blown and replace the fuser it just blows again. I think it may be time to finally retire the unit. Attached are a couple of pages I found from the combined service manual which shows the part and gives the part numbers depending on your model and voltage required.

[Dwf2008]

Thank you David.  I have noticed that if the printer is left unplugged for a few hours and then turned on the lcd display will light and flash momentarily and then go out. Subsequent on/off cycles produce nothing until it has again sat unplugged for a while. Does this offer any further clues?

[davidzuts · Accepted solution]

Not really. Something is drawing current forcing it to power off. Once the caps have discharged it then again powers on for a moment with again something drawing to much current. As I said, time to retire. Besides getting good toners for this printer is getting harder and harder since hp stopped making them over 12 years ago.

[Dwf2008]

Thanks. I have a M477 on order.