Loss of power in an HP M4555 MFP


A few days ago I was called out to work on a HP M4555 MFP machine that didn’t have any power—no lights on the control panel or formatter board, no fans, no anything. The call was through a National Service Provider (NSP) so a customer service technician had diagnosed the machine over the phone and a low voltage power supply (LVPS) was sent to the customer’s office to be replaced.

When I arrived onsite I tried a few quick troubleshooting steps and decided to go ahead and take a look at the LVPS and noticed that one of the two fuses on it had blown. Since the NSP had sent out a replacement power supply, and I already had this one out, I decided to install the new LVPS.

Typically, when you have a blown fuse, simply replacing the fuse or the board fixes the problem. Unfortunately, once I replaced the LVPS, put the machine back together, and turned it on I heard a loud popping noise and the nice smell of electrical components burning.   Continue reading

58.4 Power Supply Error in the HP LaserJet M5025 Multifunction


I was recently called out to work on one of  a HP LaserJet M5025 multifunction printer (MFP) the other day, which had the 58.4 error happen over the weekend. When the customer came in Monday morning the error was on the screen.  I recommend these steps to troubleshoot:

  1. Turn the machine off
  2.  Make sure it is not plugged into a surge arrest, power strip, or battery back up
  3. Let it sit 20 to 30 minutes unplugged
  4. Plug it back in and try again.

If the problem still occurs then the next step is to Continue reading