C6500 repetitive defect

[vlad_robas]

Hi,

I have retitive defect on print. It consists in small white line ( about one cm long and two mm wide). And it repets itself every 250 mm. I can't figure wich component has this diameter. Can you please trow me an ideea?

[blackcat4866]

Re: C6500 repetitive defect

250mm/3.14159265 = 79.577...mm diameter or 39.788...mm radius. It sorta sounds like a drum ... or a heat roller to me.

EDIT: See page K-311 of your service manual. =^..^=

[vlad_robas]

Re: C6500 repetitive defect

I had take a good look at fuser and the fixing film has that mark in it.
So I'll be ordering some part's (it is first time on this machine).

Page numbering seem's to difer.

SM.jpg

[blackcat4866]

Re: C6500 repetitive defect

Use the pdf search function for 251 (mm). =^..^=

[tulintron]

Re: C6500 repetitive defect

I had take a good look at fuser and the fixing film has that mark in it.
So I'll be ordering some part's (it is first time on this machine).

Page numbering seem's to difer.

[ATTACH=CONFIG]28731[/ATTACH]

Fusing Belt.

・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

[vlad_robas]

Re: C6500 repetitive defect

I have recived the fuser part's and replaced them. In the mean while I have got error 3508.

I have also repaced now or recently
- developer's
- transfer roller
- drum's
- filter

But I have randomly some lines. It was a blue one then red and now it remains only a black one, see the atach.
KM C6500 line.pdf Line is on front and back of page even if it is one face print and sometimes get's thicker.

I have changed drum's betwen colors with no luck. Swaped main charger, cleaned laser glass.
I had this line in the past and I did get rid of it for a while but it keep's comming back.
The only thing that is not changed are part's in the primary transfer unit and the develing units.
What are your opinions?

[blackcat4866]

Re: C6500 repetitive defect

It looks to me like a primary charge line, probably for the black imaging unit. It fits your scenario in several aspects:

1) Charge lines can be thicker or thinner depending on how many consecutive pages.
2) Charge lines can appear on the backside of the image because the line is created on the primary transfer belt before, during, and after the image area intermittently. The toner on the black drum transfers to the primary transfer roller, then to the secondary transfer roller, then prints onto the backside of the paper.
3) Charge lines print edge to edge through the voids.

A simple test would be to swap the black primary charger with the cyan primary charger, then watch your line change colors. =^..^=

[vlad_robas]

Re: C6500 repetitive defect

I have done more than that, I changed all the primary charging units with brand new ones. The line is still there is not as thick as is used to be and doesen't appear on the back side (maybe becouse is not as thick as is used to be). So im out of ideea's.

[RAI]

Re: C6500 repetitive defect

Is the line always on the bottom? Are you printing face up always? It looks like random electronic imaging issue. Maybe try reflashing firmware. I would test face up only prints to see if line shows on the front side. Then back to only face down and see if something is being written on the belt during the paper flip. Your line looks like a laser write. I'm thinking the thickness is the residual image in the secondary transfer roller and as paper passes it disperses the image out (to a thicker blurry line). Anyway just a thought.

[kalindd]

Re: C6500 repetitive defect

Is the line edge to edge?
To me it looks like you need to check the transfer belt cleaning blade.

[vlad_robas]

Re: C6500 repetitive defect

Since last post I have changed on the primary transfer:
- belt and the recovery film (blade is almost new)
- replaced the roller's in the transfer unit

Afther all this the line is still there.

Then I brushed all the led bar's that are under the charging corona and the line is gone.

Print few pages and seem's ok. Afther 10-20 heavy prints 300 gsm the line is back. Print one side and it doesen't apear on back, but it is from side to side.
I'm going crazy with this machine.
I have no knowlege about updating FW on this machine.

[copyking]

Re: C6500 repetitive defect

Ok, a long shot but here it goes..
Try changing the pressure between transferbelt and second transfer roll, you'll find settings for this under the tray settings somewhere ...
I remember having similar lines and solved them with this..

/Henrik

[vlad_robas]

Re: C6500 repetitive defect

can u be a little more specific about where should I look for that settings?

[vlad_robas]

Re: C6500 repetitive defect

I have come to the conclusion that I have to change developing unit on bk.
And I have come to that conclusion becouse I have exchanged bk and yel unit's without closing the front door and only trick the switch so that the copier will start and I have run a few pages.

[tulintron]

Re: C6500 repetitive defect

I have come to the conclusion that I have to change developing unit on bk.
And I have come to that conclusion becouse I have exchanged bk and yel unit's without closing the front door and only trick the switch so that the copier will start and I have run a few pages.

Very good vlad_robas. Reversing the revealing units show in another color.


Another case that came across was with an adhesive tape located before roller 2nd transfer. When broken, shaving in the transfer belt and cause risk in print.


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