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jrlarson67
04-08-2015, 10:58 PM
We fought this problem a few months ago and tried everything and eventually the yellow drum drive took care of it. The problem is back now, and before throwing more parts at it I would like to hear some opinions. It has had entire ITB assembly, Developing assembly, Drum, coronas, entire process carriage, both HVT's, HV contacts, and wires. Oh, and drum drive assembly. This is impossible to troubleshoot because sliding the carriage out and back in fixes it for up to 2 days.

RAI
04-09-2015, 11:43 AM
The interval of the band will tell you the source of the problem. I find all these machine suffer cross direction banding on the yellow. Drum replacement does help this type of problem. You can decrease the drum rotation time and preform a expert adj to remove any drum image burn in.

jrlarson67
04-09-2015, 05:34 PM
I'm waiting for my next visit to get examples to upload, but the problem is random, no interval. It could have one band on 12x18 sheet or 4 bands. Now the problem is the customer keeps fixing it themselves by pulling process out and pushing it back in then telling us it keeps happening. Can't troubleshoot something that is working when you get there.

RAI
04-09-2015, 06:02 PM
They are going to damage the transfer unit. My thought is that it's just an image burn in from a prior job or a humidity problem once it warms up. Either way would explain pure randomness. Expert adjust should address this. But I'm guessing your client likely has random enviromental conditions that aren't being addressed. Blame the machine. Lol

Mick01
04-14-2015, 06:52 AM
HI,
Try printing in "Line screen" rather than "Dot screen" if possible. This screen smooths out flat colours and removes most banding issues.
you will have to calibrate to this screen as your colour will be different.
Hope this helps.

jrlarson67
04-14-2015, 02:19 PM
The banding is definitely HV spikes or drum ground loss. It is nearly solid bar of yellow all the way across page even outside image area. We have since replaced yellow drum drive assembly again and problem is gone. We are currently investigating the extreme wear on the new drive assembly that just got replaced again and are replacing the bearings in the process carriage as well.

rofield67
06-14-2017, 06:11 PM
I am having same problem with a C6000, driving me nuts! as soon as you open and close process unit it disappears for about 400 prints, then its back, I tried everything including HVT2. Maybe I will swap drum drive to see what happens. Please update if you find solid fix for this nightmare problem, I will do the same.

rofield67
06-16-2017, 05:36 PM
I think I have solved this problem, I found cyan developer leaking from rear side getting on HVT connectors on real wall. I removed process unit from machine and vacuumed and cleaned all connectors with compressed air, forget about trying to do a good clean up without removing the process unit, cant get to everything with unit in the way. Two days of solid running without this problem coming back, gonna keep my fingers crossed but so far looks good.

rofield67
07-12-2017, 01:47 AM
Its back, as soon as you open and close process unit problem goes away for a while. Any input on this problem would be greatly appreciated. Thanks!

tulintron
07-24-2017, 03:36 PM
Its back, as soon as you open and close process unit problem goes away for a while. Any input on this problem would be greatly appreciated. Thanks!

Can it be something related to the rails of the process unit?


I have encountered intermittent problems twice, and coincidentally the bolts on the rails were soiled.

rofield67
11-30-2017, 10:35 PM
I am still fighting this problem on a few machines, all black issues, open and close process unit problem gone for a while. I thought it was a round issue because when I tested the drum drive shaft sticking out of front process unit ground was all over the place. Removed drum drive unit and cleaned ground plate, reinstall and check ground again, it was consistently less than 1 ohm. Problem solved for a couple hundred thousand copies and now its back again. The ground is still good. Machine is driving me crazy! Attached is a picture of the interment problem, band run front to back.

rofield67
11-30-2017, 10:38 PM
lets try this attachment again.

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