Bizhub c451 dirty copies

[ICEDRAGON]

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?

[Albonline]

	Quote:			Originally Posted by ICEDRAGON
	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?

is iron showing up in the cleaner box? is iron on the xfer belt if you stop mech during stablization? were the 2 (dead) black units oem? same lot number?

[ICEDRAGON]

What should the iron look like?

Yes both black IU were OEM, I will check the lot numbers.

The funny thing is it runs fine with the reset IU.

[ICEDRAGON]

The bad ones are from the same lot!

The new one is from a differnt lot and is printing fine now, I am crossing my fingers that it will last longer than 6,000 sheets.

[JSC]

	Quote:			Originally Posted by ICEDRAGON
	What should the iron look like?

Stick a magnetic screwdriver in the waste btl, if the machine is pulling the dev (Iron) it will be attracted to the screwdriver, if this is the case then an ICP has blown on the main board.

[ICEDRAGON]

We are 1,327 prints in on the new imager running 11 x 17 on thick 1 in greyscale mode now and no problems yet. I just hope it was a bad IU X2 and not an expensive main board, we are barely makeing it over here and own this machine with no service contract so this could hurt bad, cross your fingers...I will keep you posted.

We just had the latest firmware insalled about a month ago, could this be a firmware issue?

[ICEDRAGON]

After running 2,400 11 x 17 sheets the problem is back, black IU dumping iron on one side of the sheet.

How can we tell if its the main board for sure, we already replaced the High Voltage Unit /1 and went through three black IU, any ideas on what is causing the problem?

[JSC]

Can you post a scan of the copy quality problem?

[ICEDRAGON]

There is Iron on the sheets and in the waste box, we have decided to change the main print control board on the machine, it controls the black imager and we think its bad.

The part is on its way and we should know by tomorrow if its the bad part.

thank you for all your sugestions. :-)

[ICEDRAGON]

Hello & Happy Sunday! :-)

WE replaced the PWB assembly MC and it ran fine like normally and then after 6,000 pages the iron is back on the sheet

Now we have replaced two boards and the proble hasn't changed, any Ideas?