SC 305 & 377 MP6002

[Joe]

Hello;
We had a dealer that installed 4 of our machines MP6002, 2 of them had SC codes 305 & 377, they fixed the 305 but still struggling wuth the SC377, this is what the tech described in 1 mach...........
Serial # W863L300350R1 (our BF870):
7/23 @ 1481 copies - Began reporting SC377 errors. Machine was checked, all firmware was updated, and no further issue found on 7/25.
8/3 @ 4983 copies - SC377 returned. ID and potential Sensors were cleaned, corona wire and cleaner operation were checked. Automatic Adjustment of Drum Conditions was run and SC377 occurred again. Checked/tightened screws on drum flywheel; SC377 still occurs. Performed Engine Clear and re-entered non-default settings, Again ran SP262 and then SP3001-002 to force AutoProcess Control - SC377 occurred. Replaced ID Sensor, and again ran SP262 and then SP3001-002 - SC377 did not reoccur.
8/8 @ 6195 copies - SC377 returned. Replaced Potential Sensor and harness. Checked connections in PCU and at BCU. Stretched corona contact springs per hotline suggestion. No improvement.
This continues to occur very frequently and so far we have not found the cause. Hotline call #2034339
Any ideas for the possible solution??...Thanks

[slimslob]

Could be a drum ground problem. If drum continuity to ground is greater than 10 Ohms or varies more than 1 ohm at different points of drum rotation you may have a bad conductive bearing in the drum shaft bracket B0651137. If the continuity is extremely, you could have a bad development power supply.

[Joe]

Could be a drum ground problem. If drum continuity to ground is greater than 10 Ohms or varies more than 1 ohm at different points of drum rotation you may have a bad conductive bearing in the drum shaft bracket B0651137. If the continuity is extremely, you could have a bad development power supply.

Thanks, I'm going to recomend your suggestion, hope works, thanks again for your help.....

[keithxxiii]

I remember we had these machine that throws up weird sc-3XX codes and ended up replacing PM Parts. Then 1 tech noticed the spring behind the PCU assembly is bent an doesn't reach the contact. That was the culprit all along!

[Joe]

Could be a drum ground problem. If drum continuity to ground is greater than 10 Ohms or varies more than 1 ohm at different points of drum rotation you may have a bad conductive bearing in the drum shaft bracket B0651137. If the continuity is extremely, you could have a bad development power supply.

Hi slimslob;

Specifically, where is this drum ground to be measured? which are the points to be measured?, can you please clarify............Thanks

[slimslob]

Same as usual. From the end of the drum shaft to frame ground.