di 550 power on problem

[laxman]

Hi,

when i switch on this machine it refuse to (some times it does) every time i can hear the click sound of relay in power supply but no display.
One of friend told me to check for dry sold on power PCB, i tried that it worked for few on off and then again came to same position.
can any body help me on this?

[Hansoon]

We once had an issue with the main relay RY1 causing similar.

Hans

[WetPaper]

Could be a problem with upper fuser thermistor failing. Try removing fuser unit then power up machine. If it powers up, then you might need to replace the upper thermistor.