c7000 - Ghostly mark repeats - not coding out

**tsbservice** · 07-12-2021, 07:04 PM

Re: c7000 - Ghostly mark repeats - not coding out

Hi Mark glad you're hanging around mate.
Unfortunately I have no production machines in the field but if you need any guide for this model just PM me. You have interesting problem here and I would love to fight it in person. This is looking like something is causing a small bump on mag roller and it touches drum surface.
I'm sure other guys here will have more insights. Good luck.

**Synthohol** · 07-12-2021, 07:17 PM

Re: c7000 - Ghostly mark repeats - not coding out

first glance id check the fuser belt.
if you roll one mark on top of the next you get the diameter of the offending roller/belt/drum.

**blackcat4866** · 07-12-2021, 11:23 PM

Re: c7000 - Ghostly mark repeats - not coding out

Did you remove the red painted shipping screws on the drum blade mount? If not the drum blade will not touch or clean the new drum. I think everybody has done it at least once. 188mm is the right interval for drum cleaning. =^..^=

**raplma** · 07-13-2021, 08:22 AM

Re: c7000 - Ghostly mark repeats - not coding out

Morning all
It's a great feeling to arrive at the factory in the morning fire up the PC and see you guys many thanks for your replies.

tsbservice: So, if they ever get teleportation working I know who to call

... yeah! Thanks for the offer of the manuals I think I have all the ones for this machine. I will certainly look into whether something is bumping into the drum surface though. I do have a new whole transfer belt assay, I've just not the cleaning unit for it so, reluctant to put it in without renewing that too.

Does anyone know if the TB assay from a c5501 can be used in the c7000, I know they made a few tweaks in the upgrade, but will it work well enough that if I put it in the c7000 it will at least work, so I can then rule in/out the TB?

Synthol: Thanks for the pointer of the fuser, I hadn't thought to check that as I was convinced it was in process. Having checked it, there are a couple of marks but they don't correspond to the marks on the paper. I do have a spare fuser on the bench, so will finish rebuilding it and swap over to rule out that part.

blackcat: Oh yes those cheeky little blighters. Yes I have removed those, I have a little pile on the machine to remind me, and yes I too have forgotten to remove them in the past!! Yes indeed the distance corresponds to the drum circumference, which is why I initially changed the drum, but still get the same mark irrespective of the drum installed.

It's just such a weird mark, as if someone is pouring a liquid down the drum, but of course it's in the wrong direction...

Thanks again, most appreciated.
Mark

**Toxic** · 07-13-2021, 08:48 AM

Re: c7000 - Ghostly mark repeats - not coding out

I dont see good from photo, is that mark only one color (black) or is it mixed color?
Which drums you use , i remember long time ago we all have problem on C5501 and DU-102C with cleaning blade factory problem?
It is little confusing you said repetition mark is 186-196mm, is it really changing distance, it should not if you measure from mark start point to second mark start point?
I would try to put other developing unit.

Failed mechanical part.
・Approx 188mm pitch: Damage on the drum surface.
・Approx 251mm pitch: Damage on the fusing belt
・Approx 53mm pitch: Developer conveyance failure of developing sleeve.
・Approx 95mm pitch: Soiled second transfer roller

**tsbservice** · 07-13-2021, 09:03 AM

Re: c7000 - Ghostly mark repeats - not coding out

Originally posted by Toxic

I dont see good from photo, is that mark only one color (black) or is it mixed color?
Which drums you use , i remember long time ago we all have problem on C5501 and DU-102C with cleaning blade factory problem?
It is little confusing you said repetition mark is 186-196mm, is it really changing distance, it should not if you measure from mark start point to second mark start point?

Failed mechanical part.
・Approx 188mm pitch: Damage on the drum surface.
・Approx 251mm pitch: Damage on the fusing belt
・Approx 53mm pitch: Developer conveyance failure of developing sleeve.
・Approx 95mm pitch: Soiled second transfer roller

@Toxic
On Mark's picture it looks like 186mm distance but yeah pretty close should be the drum.

@Mark
Blakes-7-TV-Series-1978-Liberator-Teleport-Bracelet-1.jpg

**raplma** · 07-13-2021, 11:58 AM

Re: c7000 - Ghostly mark repeats - not coding out

The mark is only K black, there is no CMY.

I mentioned that the spacing is variable, that would be because the shape of the mark varies each time, so there isn't a set datum to measure each mark. But they will be 188mm so yes the drum has something to do with it, and indeed was why I initially swapped the drum, but changing the drum has no effect. The drums are DU104's, yes we had the issue with the DU102's back in the day and have since only used 104's even on the c5501's and c6501 machines we had.

The strange aspect for me is that the mark is different each time, it isn't a consistent mark... could the TB be flapping - for want of a term - hence asking if a c5501 unit could be used.

c7000 Ghost marks 2.jpg

**raplma** · 07-13-2021, 05:21 PM

Re: c7000 - Ghostly mark repeats - not coding out

Minor update
I can rule out the fuser as in swapping it the mark is still there.
I have been panic stopping the machine and the mark has always has just passed on to the paper, so will try again tomorrow to see if I can stop it when it is on the drum or TB.
FYI the mark gets progessively bigger and more pronounced the longer the job runs, stop and restart and the mark resets as it were, run a single sheet at a time and the mark is bearly visible...curious.
Many thanks for your suggestions and advice, most appreciated.
Mark

**tsbservice** · 07-13-2021, 05:48 PM

Re: c7000 - Ghostly mark repeats - not coding out

Mark when you print CMY separations from Service mode is the defect present? If not that should rule out(at least that's my theory)TB and leaves only black drum/dev and surrounding as possible culprit.

**Synthohol** · 07-13-2021, 06:43 PM

Re: c7000 - Ghostly mark repeats - not coding out

ive seen the coronas vibrate causing drum contact, you normally will see a kind of grid pattern but try swapping coronas around, see if the issue changes.

**blackcat4866** · 07-13-2021, 11:35 PM

Re: c7000 - Ghostly mark repeats - not coding out

Similarly I was going to suggest swapping cyan and black drums. I'm still stuck on drum cleaning. =^..^=

**raplma** · 07-14-2021, 08:25 AM

Re: c7000 - Ghostly mark repeats - not coding out

Morning all...
Thanks again for your replies, most appreciated.

tsbservice: The mark remains irrespective of the job sent through, CMY separations, no image anything. So yes so I agree, it's unlikely to be TB related.

Synthohol: Ideed, this is where I started when the problem first occurred, replacing the drum and corona with new items. But I think you and blackcat have given me the next thing to try, I know the drums/coronas of the CMY are fine, so as suggested swap them over and see what happens. The vibration concept I'd not thought of, so if swapping doesn't change anything, which I suspect it won't, looking into whether something could causing an oscilation of the drum/corona is a great idea, and kinda makes logical sence as to the shape of the mark, and why it gets more pronounced as oscilations by nature amplify.

Thanks again
Mark

**raplma** · 07-14-2021, 12:29 PM

Re: c7000 - Ghostly mark repeats - not coding out

Sorted!...he says while grasping for some wood...just need to run a full job to make sure.

and the winner is....

Well not totally sure TBH.

I liked the suggestion of an oscilation causing the mark, so checked the drum shafts for any signs of play in the motor housing bearings, after all this is a high miler, but nothing of note. As suggested I swapped the cyan/black drum and corona's over, and ensured that they were snugly seated so that they couldn't oscilate. However...what I also noticed is that the TB assay didn't sit smoothly into it's support blocks when re-installing, you know how it usually just drops in, so cleaned them out put it all together, ran a load of test pattern sheets through and 200 sheets later no mark on any of them.

So, it could have been the drum/corona, or it could have been the TB oscillating on a bit of git in the groove, who knows.

What I do know is as usual you've come up trumps, so massive thanks for throwing ideas and suggestions at this, most grateful!

Until the next issue

Mark

**blackcat4866** · 07-14-2021, 01:15 PM

Re: c7000 - Ghostly mark repeats - not coding out

Congratulations! Thanks for sharing. =^..^=

c7000 - Ghostly mark repeats - not coding out

c7000 - Ghostly mark repeats - not coding out

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment