View Full Version : Miscellaneous Very Poor quality images

Custom Search

02-16-2011, 01:25 PM
Can anybody suggest what to do about the attached images, image units and transfer belt have been changed but as you can see the image is awful.

02-16-2011, 02:34 PM
Does the fuser rollers have wrinkles in them?

02-16-2011, 02:37 PM
No fuser rollers are fine

02-16-2011, 02:43 PM
There is a printhead FOC on this model. But I dont think all of them went bad at once. What does the demo page look like?

02-16-2011, 10:21 PM
Whats the life on the drums have they been chipped ?

See this lots on drums that are at the end of life. Since the cyan sorta looks ok I'd put that in one of the other slots like the magenta swap the chips round just do a single half-tone just to see if it is the drum or really get known good drum just to rule it out first.

Definitely dev related tho that throws the copy quality off like that would love to know why but a new drum always seem to cure it for us. You could try forcing some toner into the drum from service mode just to see if there's any change.

My theory on the chipped drums is the tcr goes to whack so the machine either has too much toner or too little and eventually sucks the drum dry but I'd love to hear what everyone else thinks as I see this all the time.

02-23-2011, 04:15 AM
If CMYK having the same problem, most likely there must be one of the gears had chip off. Please check tranport section and try stopping the machine have way and see if image form on transfer belt is clear.

03-01-2011, 12:13 PM
I've attached the Demo so you can see, the IU haven't long been replaced so I can't see that they would be at the end of their life, although saying that if you stop the machine in cycle and check the image on the CMK IU the white lines to show on them, they also show on the Transfer belt if you stop it further on in the cycle. Fuser unit is fine.

03-01-2011, 01:20 PM
Would tend to agree with above posts. Problem is in all 4 color. You have verifed that problem is before first transfer, IU's have been replaced, I would look closer into the drive section. Timing must be off. Broken gear, failing motor, bind in system. Havent seen this before.

03-02-2011, 12:41 PM
Could be something up with the transfer belt. Put a used belt in and see if that corrects the problem.

I tend to disagree with the other posts about a broken gear. I could see that if the lines were parallel to the feed direction, but not a diagonal pattern.

03-02-2011, 01:16 PM
I ask, did this happen immediately after changing the IUs and transfer belt or a little while later?
It looks like a situation when developer reduces in the developing possibly due to a failure in the
biasing system so the remaining developer got fried.
If this happened a little later, then check the contacts of the HV unit or change the HV unit along with the defective units.
Otherwise check the machine's main drive.

03-02-2011, 09:53 PM
I've seen this many times on IU's after being reset with zero'd chips.This fault shows up @ about 30%(resetting with zero chips causes dev to be charged and completely fecking up the TCR)New units always fix it.
Unusual that all 4 iu's go at same time though, possibly a main brd issue(seen sorta similar fault on C451 that main brd sorted)

03-03-2011, 03:07 AM
i had this pattern before and mine was the fuser roller part not the belt

03-03-2011, 10:33 AM
It isn't on them all the cyan is perfectly ok, the units were new units not chipped units.

03-03-2011, 11:59 AM
I've noticed that it doesn't happen on Cyan. Seems like the other IUs lost developer.

Did you check for developer on the waste toner bottle? I'd guess you've got some HV problem.

03-03-2011, 01:23 PM
When you look down into IU units you can see the lines on the side on the unit, is this due to lack of developer?

03-03-2011, 01:28 PM
Could be due to the developer being projected out of the unit.

Stick a magnetic screwdriver tip onto the waste toner bottle and check if developer comes out with it.

03-03-2011, 02:18 PM
I did the screwdriver test and yes developer comes out with it?

03-03-2011, 11:25 PM
Then maybe you've got a bad HV board? I'd start checking the connections, and if doesn't solve it, try to exchange the HV board with a new/working one.

Maybe some other techs can give some more advise on this, since I never experienced this myself.

03-04-2011, 12:48 AM
I don't know this model very well, but I had a Xerox with 2 DV units messing up at the same time, both with problems like you're experiencing. Might be worth a look at the mag rollers to make sure developer is in ample suppl and evenly distributed.

03-09-2011, 06:31 PM
i had this on a m/c and a new dev tank sorted the issue straight away. it seems the issue is caused by lack of dev in the tank, but im not sure why - may be tcr signals wrong????

03-09-2011, 06:57 PM
Do you shake the IUs before installing them? I suppose that compatted developer have broked the seals tha retains the developer into the units.

03-13-2011, 08:55 PM
Are the imaging units New or refurbished? Were they changed at the same time? I have seen this in some Canon devices as well. Changing the imaging units corrected the problem. Believe that the charging bias inside the IU is bad or being shorted out, possibly by waste feedscrew auger as lines/stripes are diagonal. I thought this was suggested earlier but did not see response posted.

03-13-2011, 11:35 PM
I think the reason that you can see it on the IU's and the Transfer belt is that it hasn't transfered properly to the belt. For all your IU's or laser's to be presenting the same problem is lottery numbers unlikely. You need to be looking at your image transfer belt. If not that then something connected to it - Earthing, Charging, High Voltage Board or something oddball like foreign body discharging (staples, paper clips etc..) or something else just as weird.

03-15-2011, 04:04 AM
Had u done the gradiation/gamma? Pls counter check the flat cable(white colour) behind the m/c and see whether the pins is sitting correctly.

03-15-2011, 11:43 AM
Looks like your iu lacks toner, i would suggest to go to service mode and load toner on MYK (four times each affected color), then execute running mode for 5 minutes. if not it could be a HV problem.

Custom Search