Bizhub c451 dirty copies

[Albonline]

try changeing hv2 first!!!!

[Stirton.M]

Hello :-

Any thoughts?

Check storage of IUs....or how they are being delivered to you. There could be physical damage to the housing and the developer bias contacts internally. I've seen this myself a couple times.

TSB refers to HV1 as defective if you are getting starter on your prints...though I doubt that is related to your problem.

Check for developer bias contacts...yours might be damaged on that machine. It is highly unlikely the dev units are at fault if this happens constantly. Also, be sure to completely clean the entire area under the IU to eliminate any errant bias to earth ground. Check your contacts to the HV boards with relation to the bias contact in the back.

Also, in some cases, I have found that the lock latch can be problematic on this series...451,550 and 650. The black IU tends to drift and lose all bias, the net result is poor black reproduction and P codes related to it.

[B0265]

ICEDRAGON, did you find the solution?

[Having a ball]

Hi

Hello :-)

I have a c451 that keeps killing black IU, they run for 5,000 or 6,000 pages and then start dumping devloper all over one end of the sheet.

I have replaced two black image units so far (in less then a week) and I am waiting on a third unit. We replaced the High Voltage unit /1 and no help. The only black imager that works is one that had the chip reset and it's drum is getting old.

Any thoughts?

Check the lot numbers on the IU box as there is a manufacturing issue with the distance between the mag roller and the PC drum maybe all thses IU's are the same lot number if so check with KM.