sc 543 overheat code on mpc3000

**duane@pbbsinc.com** · 03-20-2014

I am at my wits end with this service call I have rebuilt the fuser twice with new thermistors and thermostats, I have changed the power supply board, I have changed the thermopile, I have changed the I/o board, and next one in line is the bicu board.
The machine will work sometimes without a code for 4-5 days or even two weeks.
It is a Ricoh MP-c3000 not sure why sc543 keeps popping up. I even put the copier on a voltage regulator box. Customer called back within a day she said that she had an electrician out and said power was good.

**Gamut** · 03-20-2014

software error!

1: First update firmware to latest

2: if still no go> replace PSU then IOB and finally to where you are BICU.

**Ben Around** · 03-20-2014

Originally Posted by Gamut

software error!

1: First update firmware to latest

2: if still no go> replace PSU then IOB and finally to where you are BICU.

We have had problems with the wiring harness in the fusing unit cause this.

**Coptech** · 03-20-2014

Check the fusing lamp with dual filaments. My bet is one of the filaments is bad. After that, have had the fusing connector on the main body itself get loose and throw intermittent codes.

**kelvin3892** · 03-22-2014

Replace PSU

**neergish** · 03-24-2014

I had this kick my ass in a machine that was a good 2 hour drive away down a very windy tourist buss filled road.

After hunting down a few threads here I replaced the entire fuser, problem went away

**TonerMunkeh** · 03-24-2014

Originally Posted by neergish

I had this kick my ass in a machine that was a good 2 hour drive away down a very windy tourist buss filled road.

After hunting down a few threads here I replaced the entire fuser, problem went away

A necessary evil sometimes. I had one of these things popping 553 for a couple of months. Replaced everything in the fuser, and I do mean everything. Still 553. Replaced the fuser and the code stopped.

**duane@pbbsinc.com** · 03-26-2014

Originally Posted by TonerMunkeh

A necessary evil sometimes. I had one of these things popping 553 for a couple of months. Replaced everything in the fuser, and I do mean everything. Still 553. Replaced the fuser and the code stopped.

I have pulled the copier in the shop and given a loaner so I can properly repair the copier in a stress free environment.
Upon removal of the fuser for the third time I noticed the bushings on the hot roller under the belt closest to the machine to be melted to the bearing.
I replaced again and rebuilt the fuser with a new belt and bushings and bearings and reset the machine code it kicked up on our power source.
My theory is that I fixed overheat with one of the two boards I replaced the power supply or the I/o board and did not recheck fuser for issues as I already rebuilt it twice in the field. I think the relay on the power supply was sticking and melted the bushings again.
The copier is going on a 48 hour running with no sc543.

**CrapAimer** · 03-26-2014

I have replaced the bushings and the belt which has got rid of problem, also have heard the wiring loom is at fault, I have also taken the fuser and swapped it over into another machine and it has worked.