[CQ] C300i image quality problem color horizontal lines

[satisfactionbg]

Hi,

I have a C300i with a strange problem, it has around 110k color pages 60k b/w.
Lines on color prints perpendicular to the moving direction of the paper.
You can see the on all CMY but not on K.
I did changed the K drum.
Tried new DR-Y, swaped TBU, HV unit, Power supply from another machine with no luck.
Next thing in my mind is PHU, but i don't see how it can affect only CMY and no K.
I did have a couple of the i series with missing colors on half of the page due to the retract mechanism getting stuck i think but the TBU swap did nothing.
Any ideas?
some photos:
IMG_20231114_173057.jpg - Google Drive
IMG_20231114_173244.jpg - Google Drive

https://drive.google.com/file/d/1k2M_dLZ8q3eTGmG9aTnAUFXASemVCUKs/view?usp=drive_link

Thanks!

[tsbservice]

Re: C300i image quality problem color horizontal lines

Hi,

I have a C300i with a strange problem, it has around 110k color pages 60k b/w.
Lines on color prints perpendicular to the moving direction of the paper.
You can see the on all CMY but not on K.
I did changed the K drum.
Tried new DR-Y, swaped TBU, HV unit, Power supply from another machine with no luck.
Next thing in my mind is PHU, but i don't see how it can affect only CMY and no K.
I did have a couple of the i series with missing colors on half of the page due to the retract mechanism getting stuck i think but the TBU swap did nothing.
Any ideas?
some photos:
IMG_20231114_173057.jpg - Google Drive
IMG_20231114_173244.jpg - Google Drive
IMG_20231114_173042_1.jpg - Google Drive

Thanks!

Few questions if you don't mind. Why you tested new Y drum unit? Yellow is weakest color and hardest to see anything image related. This yellow drum unit was brand new OEM from the unopen box and not from shipping damaged machine or from working machine - yes or no?
I'm asking because at 110k I would suspect color drums are a bit of overused especially when machine is clicking more colors than monochrome.

[mojorolla]

Re: C300i image quality problem color horizontal lines

Hi,

I have a C300i with a strange problem, it has around 110k color pages 60k b/w.
Lines on color prints perpendicular to the moving direction of the paper.
You can see the on all CMY but not on K.
I did changed the K drum.
Tried new DR-Y, swaped TBU, HV unit, Power supply from another machine with no luck.
Next thing in my mind is PHU, but i don't see how it can affect only CMY and no K.
I did have a couple of the i series with missing colors on half of the page due to the retract mechanism getting stuck i think but the TBU swap did nothing.
Any ideas?
some photos:
IMG_20231114_173057.jpg - Google Drive
IMG_20231114_173244.jpg - Google Drive
IMG_20231114_173042_1.jpg - Google Drive

Thanks!

I would agree with TSB, take a look at the color drums. The solid tones are good, but the lighter halftones show the lines.
Also, if you zoom in on this photo: IMG_20231114_173244.jpg - Google Drive, you can see black speckles applied over the colors and speckled deletions in black, indicating the fuser should be looked at.
We have had drums fail as early as 60k on this model so I would not be surprised if the color drum units were the issue.

[Rewind!]

Re: C300i image quality problem color horizontal lines

We just had one of our techs with this same exact issue this morning on a C360i (318k total CMY drums @ 50%), he also swapped out transfer belt unit S23111415351.pdf with no change, reseat all connections, replaced main board, but changing the charge AC output find adjustment to correct the image issue (Service/Image Process Adjustment/2nd page/Chage AC output Fine Adjustment. He set these values to +8 for the CMY and left the K at 0. This points to the HV unit being the issue. Will advise once this is changed.

JC

[hidius]

Re: C300i image quality problem color horizontal lines

Pull out the colour drums and check the charge and cleaning rollers

[satisfactionbg]

Re: C300i image quality problem color horizontal lines

Few questions if you don't mind. Why you tested new Y drum unit? Yellow is weakest color and hardest to see anything image related. This yellow drum unit was brand new OEM from the unopen box and not from shipping damaged machine or from working machine - yes or no?
I'm asking because at 110k I would suspect color drums are a bit of overused especially when machine is clicking more colors than monochrome.

Well honestly I should have tested on another colors. Would do on the next visit. Yes, the Y drum was brand new original. You are probably right that the drums are a bit overused. What confuses me is the directions of the lines. Usually they go in the direction of the paper.

[satisfactionbg]

Re: C300i image quality problem color horizontal lines

We just had one of our techs with this same exact issue this morning on a C360i (318k total CMY drums @ 50%), he also swapped out transfer belt unit [ATTACH]60494[/ATTACH] with no change, reseat all connections, replaced main board, but changing the charge AC output find adjustment to correct the image issue (Service/Image Process Adjustment/2nd page/Chage AC output Fine Adjustment. He set these values to +8 for the CMY and left the K at 0. This points to the HV unit being the issue. Will advise once this is changed.

JC

Thanks for the reply.
I did swapped the HV unit with used good one but no change on quality. However I didn't change any settings in the service menu. I will definitely try playing with the AC fine adjustment.

[satisfactionbg]

Re: C300i image quality problem color horizontal lines

Pull out the colour drums and check the charge and cleaning rollers

I did that and surprisingly they look just fine for 110k.

[satisfactionbg]

Re: C300i image quality problem color horizontal lines

I would agree with TSB, take a look at the color drums. The solid tones are good, but the lighter halftones show the lines.
Also, if you zoom in on this photo: IMG_20231114_173244.jpg - Google Drive, you can see black speckles applied over the colors and speckled deletions in black, indicating the fuser should be looked at.
We have had drums fail as early as 60k on this model so I would not be surprised if the color drum units were the issue.

Good eye. These speckles went away with changing the K drum.

[Gift]

Re: C300i image quality problem color horizontal lines

perpendicular to the moving direction

Does it men in or across running direction?

Looks like the issues is originated by the "magenta involving" parts (probably dirty laser or drumunit issue - dv is probably more unlikely) - of yourse you'll see bright lines in red or blue samples since magenta is just missing in the color mix. Kind of funny to start with bk and yellow stuff, guess you come from a different field of expertise

Well as a tip: I'd probably start and clean laser glasses, next step is rule out the drum unit by swapping it with another color and see if the image error shifts to that color.

In case it's across running direction you might have issues with voltages - check them in tech menu, especially if magenta related values are way off. This can happen if you use new drum units without resetting them or just resetting old units via chip. These machines are compensating age/wear during the lifetime of the consumables (specially drum units) by shifting the voltages over time.

[satisfactionbg]

Re: C300i image quality problem color horizontal lines

I visited the machine today and it was working properly.
Maybe it needed some time after replacing the HV unit or there is bad contact somewhere

[Rewind!]

Re: C300i image quality problem color horizontal lines

Just adding into this thread. We replaced the HV board and the issue still persisted. Following the electrical diagram, all voltage and image formation is processed by the expansions control board, which runs the PH unit. We are scheduled to be onsite this week to replace this board. Again, going into the unit and setting the values in the high voltage fine adjustment corrects the issue but has all your values maxed out, when they should be at 0.

JC

[tsbservice]

Re: C300i image quality problem color horizontal lines

Just adding into this thread. We replaced the HV board and the issue still persisted. Following the electrical diagram, all voltage and image formation is processed by the expansions control board, which runs the PH unit. We are scheduled to be onsite this week to replace this board. Again, going into the unit and setting the values in the high voltage fine adjustment corrects the issue but has all your values maxed out, when they should be at 0.

JC

Thanks for update JC. Interestin first time I hear about that board may being defective.