Have a KM 2560 at power up,"program loading", atfer 5 sec's touch screen goes black. op panel is totally nonfunctional. Tried 3 different panels, HDD,main code dimm,will not take firmware.pspcb is out putting correct dc voltages, durin warm-up all motors and fans operate. Any suggestions?

How about the main charger? I have seen a buttload of main chargers ark out & cause weird things to happen, check the drum ground, main charger contacts at rear inside machine. Just a thought.

Try one of the old-time Sharp tricks. Remove all the accessories that you can and still have a copier, then see if it will boot.

If yes, install the accessories one at a time, until it won't boot, then you've got your culprit.

There have been a few cases where all the accessories are back on, and the problem is gone. Where did it go? I have no idea, but the problem never came back. =^..^=