MPC6502 SC670 - Solved

**MitchD** · 11-08-2016

Just giving everyone a heads up on a SC670 I had the other day on a MPc6502.

Basically I arrived to a machine that would not come to ready and after 5 min or so would code SC670. After pulling the rear covers and reseating all the connectors I concluded I had lost power to the BICU, IOB, and PFB. The controller would turn on but none of the other boards would receive power. All fuses on the AC power board tested good. Per Ricoh tech support hotline we opened all covers and rebooted the machine, It came to ready. After closing the covers one by one I found the machine would code again after closing the main drawer.

After checking all the wires I found the thermistor wire pinched on the fuser causing a short when the drawer was closed. I rerouted and everything is working great.

Just wanted to pass along my findings for everyone.

**slimslob** · 11-09-2016

And another potential problem with these beasts.

**MIKON** · 11-09-2016

Thanks. ....

**MitchD** · 11-09-2016

Originally Posted by slimslob

And another potential problem with these beasts.

Agreed, Still way better than the MPc6501 tho

**Counsel** · 11-09-2016

isnt there a TSB on this regarding the drawer pinching some wire harness.

**bob marley** · 11-09-2016

Originally Posted by MitchD

Just wanted to pass along my findings for everyone.

thanks

**mrwho** · 11-10-2016

Originally Posted by MitchD

Agreed, Still way better than the MPc6501 tho

I'd gladly replace the 6500 and 6501 I have for 10 of those...

**anothertech** · 11-11-2016

Yeah, so far these 6502's are much better that the 01's or 00's

**MitchD** · 11-11-2016

Originally Posted by Counsel

isnt there a TSB on this regarding the drawer pinching some wire harness.

I didnt see one for the MPC6502 but did happen to run across it for the C5100.

IMG_5050.jpg

**Lagonda** · 12-08-2016

Thanks for the heads up on this one Mitch. My SC670 turned out to be a faulty AC Drive Board. The field techs spent a lot of time swapping controller , IOB, IPU etc following the theory that one board wasn't talking to another but got nowhere. Dragged the box back here to the workshop and I did some reading first and came up with your post which led me to check the power supply. Yep, one of the 5v rails was dead so some of the boards weren't communicating as they were never being turned on. Half an hour with the multimeter found that the AC Drive wasn't fully powering up the PSU ECO and PSU FW.

The trick to this game is to read everything you can first but to start fault finding with an open mind. Be prepared to admit that you've gone down a blind ally and go back to square one and start again. Too often techs get one fixed idea in their head and spend hours even days trying to prove wilder and wilder theory's.

One again thanks for pointing me in the right direction.