upgrade the firmware or replace the defective thermostat. There may have been an update to move that thermostat a little further away from the roller with washers.
Copier will warm up completely and make copies but within 30 minutes will pop the code. I have already changed the main and sub thermistor for the upper roller. Also, when I put the fuser in another machine the code still occurs which would limit the problem to the fuser. Any suggestions?
upgrade the firmware or replace the defective thermostat. There may have been an update to move that thermostat a little further away from the roller with washers.
not looking in my SM but off the top of my head. h4 02 is a specific heat lamp low temp signal. First thing is set all heat temp values back to factory defaults. Sharp always run best there . Don't change from factory settings (unless your talking about sharps horrible c dragon machine) 2nd look in book and find exact lamp that that code is for .Then replace that thermistor , heat lamp, check all conections to it ,temp breaker canister then the ac triac that is on the ac pwb that controls the large ac current to the lamp from a small dc signal generated from the pcu pwb to control it all. That's it it simple! I'm remembering that it uses a triple lamp setup 1) end filiments for 11" paper width and 2)center filament for 8.5 and 3) a warmup lamp to facilitate quick warmup...3 lamps 3 thermistors 3 triacs 3 control curcuits. I think by memory not looking in book.