C35 skewing

[JR2ALTA]

Any known issue for laser or paper path skewing?

Device has less than 10k. skew varies between 3 and 8 mm from prints, glass and adf.
Already replace convey guide from knowledge base

Thanks in advance!

[blackcat4866]

Back in the day, before you could do internal prints (analog), we would place a piece of black tape across the primary charge unit. If the void was straight with the paper the cause was optical. If the void was skewed with the paper, then it was a paper skew. Of course, with digital technology that void would now be a black line. It also works by taking a sharpie and making a mark on the slit glass separating the optics from the drum.

Optical skew or paper skew?

More specifically does the skew appear on internal prints? If yes it's a paper skew. If no, it's optical.

Now take it a step further. If optical, is the skew caused by the scanner alignment or the laser alignment. If the scans are skewed, then it's the scanner. If the scans are straight, yet the skew is still optical, the laser is out of alignment.

Narrow it down a little, then come on back. =^..^=

[JR2ALTA]

I said skews prints, glass and adf.

Not really looking for theory just any known issues to avoid shotgun ordering

[Hansoon]

I think Cat gave some valuable information to find the cause. Not always there is a simple ready made solution to be picked from a list for every problem.


If optical, is the skew caused by the scanner alignment or the laser alignment.

JR2ALTA mentioned that its happening with prints too. That rules out the scanner.

Knowing the C-35 only remotely I would guess that it is a paper path/feed problem.

Hans

[blackcat4866]

Ok, so it happens on prints. Do you have multiple paper sources? Try all of them to determine which are affected. It's probably not a laser skew, because laser skew would not vary, it would stay exactly the same. So it's a paper skew.

On this machine its a relatively short path from the tray to the registration rollers. Anything from loose tray guides, to label adhesive on the guides, to uneven pressure on the registration rollers can cause skewing.

And No I've never seen specific cases of paper skewing on a bizhub C35, but I can think my way through it. And so can you.
And I'll help if you'll let me. =^..^=

[JR2ALTA]

Sorry for the misunderstanding. It wasn't meant to come across lazily. The device has been looked at by a couple of techs, the problem comes and goes. Sometimes skews, like noises, have a particular point of failure that are unusual but have been experienced by others, especially when they have such a low copy count.

[SmellsHot]

Have you swapped out the paper tray? I just had one the other day skewing from the main tray, because the little felt pad thing on the rear paper guide was coming off and interfering with the paper leaving the tray(causing a drag on the one side) Also with such a small tray capacity, the paper being loaded could have a bent corner in the stack, causing the tray to lift unevenly...this too will cause skewing. BTW I hate intermittent issues :)

[Spratt]

Had one skewing that was caused by uneven pressure on the vertical transport rollers on tray 3. The shaft of the roller isn't held very securely and the pressure seemed to fluxuate from front to rear causing the skew. Only cure found was to replace the tray ( more cost effective than the man hours)

[blackcat4866]

Have you made any progress Jr2? I have a few of these in the field, and would like to learn from your experience. =^..^=

[Gaffers01]

One thing to check is the fuser guide, I had a C35 a couple of weeks ago with similar issue and the guide was broken on one end.

[JR2ALTA]

Thanks for the input, the machine got thrown back to sales, but may just be the tip of the iceberg. We have skews popping up almost weekly, and that's only the customers that notice or care. I have no silver bullet yet, I will check what others mentioned. My big problem is that the paper itself seems to feed squarely past the transfer belt, so that leaves me in the Twilight Zone since there is no one laser. http://www.copytechnet.com/forums/konica-minolta/57472-bizhub-c35-skewing.html

[Don N.]

Thanks for the input, the machine got thrown back to sales, but may just be the tip of the iceberg. We have skews popping up almost weekly, and that's only the customers that notice or care. I have no silver bullet yet, I will check what others mentioned. My big problem is that the paper itself seems to feed squarely past the transfer belt, so that leaves me in the Twilight Zone since there is no one laser. http://www.copytechnet.com/forums/konica-minolta/57472-bizhub-c35-skewing.html

We just started picking these up off-lease. Two with 40~60 k totals. One skews on prints but not obvious enough for cust to know or care. There is a KMBS bulletin about the conveying sheet deformed by lifting from rt. side. The manual says a loop is produced at regist roller to fix skew but I've found no loop adjustment in service mode.

[tech51]

Ive got nearly 300 of these on my area so take the following as hard won experience!!
The rubber feet fall off from the right hand side of the machine.
The felt pads come off the side guides.
The locating pins snap off from tray 2 (the main tray, not the accessory tray). The plastic guides that lead up to the synch roller get burrs and nicks in them.
The feed roller bushes and the springs on the lift up tray go weak or wear.
The bushes on the synch rollers go tight.
Amongst other things any or all of these things will cause a skew or jam issue.
There is a modified tray 2 available which is an improvement and I would change it if any parts are broken on the tray.
Having said all of that please remember it is a printer and a small amount of skew is inevitable.

[Hansoon]

Having said all of that please remember it is a printer and a small amount of skew is inevitable.

Sounds apologetic as if coming from Chaching-Factory errr... KonicaMinolta. However, since decades printers are being build without the "inevitable" skewing.........

Hans

[tech51]

Sounds apologetic as if coming from Chaching-Factory errr... KonicaMinolta. However, since decades printers are being build without the "inevitable" skewing.........

Hans
Well Hans what I really meant was that any copier or printer will skew a little. It's a fact of life from the C35 to the C8000, it's just a matter of what's expected by the customer and how we as engineers manage those expectations. I personally am not going to spend hours attempting to fix what cannot be fixed. If its within specification then it's OK. And that applies to any make or model of copier/printer you care to mention!