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ICEDRAGON
10-13-2009, 04:00 AM
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
10-13-2009, 05:56 PM
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
10-13-2009, 06:41 PM
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
10-13-2009, 07:19 PM
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
10-13-2009, 08:25 PM
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
10-14-2009, 12:28 AM
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
10-14-2009, 02:50 PM
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
10-14-2009, 07:48 PM
Can you post a scan of the copy quality problem?

ICEDRAGON
10-14-2009, 08:15 PM
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
10-18-2009, 04:04 PM
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?

ICEDRAGON
10-18-2009, 05:51 PM
How can we get a picture into this message area for you to view and give us feed back, its basicly dumping developer on the top part of both sides of the page after we run around 5,000 pages on a new Black IU, we have changed the Transfer Belt, the black IU three times, the fuser, the PWB assembly MC and the High Voltage Unit /1 and the problem just keeps coming back.

Please some one help!

thuo
10-19-2009, 04:11 PM
can you try to set toner replenishing mode to auto

Si@danwood
10-19-2009, 09:14 PM
I presume that you have tried a new transfer belt at some point?

rprem
10-20-2009, 12:46 PM
hi friends

I got the same problem in 253 machine,wt was the machine yeild u r changing the drum for the first time wt makes u to change the drum
if u get error codes so u r changing the drum
reply me

Albonline
10-20-2009, 02:12 PM
sorry for the delay. on vacation. i would suspect the other hv unit. we had quit a few of these units have cascade failures. takeing out hv1 hv2 and mcb . replacing 1 unit at a time just ruined the new unit. you may need to replace all 3 together.sorry for the bad news!

Albonline
10-20-2009, 02:14 PM
try changeing hv2 first!!!!

Stirton.M
10-21-2009, 01:38 PM
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
12-16-2009, 12:04 PM
ICEDRAGON, did you find the solution?

Having a ball
12-16-2009, 01:14 PM
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.

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