cs 543 ricoh 1045 just for sef (second tray A4)

[hooman23]

i have strange problem with my ricoh copier . when i m using second A4 tray (sef) after 20 or 30 copy i got 543 error i replaced thermistors 2 times and nothing changed after that i replaced thermostat, hot roller, pressure roller , fusing lamps but the problem still exist...
can someone help me to solve problem
thanks

[slimslob]

Power supply, BICU, IOB.

Considering the age of the 1045, best choice is to replace the machine.

[hooman23]

As a temporary check i replaced the fusing unit with another copier and there is no problem copying more than 200 paper.. there should be something inside fusing unit that cause the problem ... any suggestion?

[slimslob]

Dirty or loose connections for the thermistors. I have had to replace the couplers that they plug into.

Dirty or cracked main fusing unit connecter. They have been known to develop small crack or micro fractures. As the connector heats up during a long run, connection is lost.

I am sure that you have already checked the screw connection for the lamps.

[hooman23]

REPLACED fusing unit connector . problem solved