HP Color LaserJet 8550 no display no lights

[TheBearAk]

I have a 8550 that when powered on, it sounds like it is going through the normal startup routine and fans are running, but the LCD display is blank, the ready/data/attention LEDs are not lit ever, and the network card never shows link or data LEDs. I tried the print engine test and it doesn't do anything either.

My guess is the 5 volt side of the PSU has gone out. All the other noises are related to the 12 volt (fans) and other voltages that run the motors.

Anyone have any other thoughts?

[TheBearAk]

One other possible symptom that I don't know what to make of it, but when I hit the power switch to turn it off, the fans continue to run and I've let it run for 20 minutes thinking that it might be some sort of cool down stage.

[cs_steve]

That would be my thought as well, to try replacing LVPS ...

[redcow]

On Power Save or Power Off, fans FM1 and FM2 will stay on for no more than 30 minutes.