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copytechman
11-02-2015, 05:54 PM
Hello all! Looking for input on this one.

Latest firmware installed, prints are fine but towards the trail edge especially on 11x17 or any long paper the image stops being square to the edges. Leading edge is within 1/2mm all the way across but by the time its at the trail edge it deviates by as much as 2mm from front of machine to the back. As a long shot I swapped in a brand new fuser with no change, there's no colour registration issues aside from the skew.

Can't see it being the printhead as it should be skewed by same amount @ leading edge.. Shouldn't it?

Further info: This is from internal prints as well as normal prints.
Belt unit is fairly new but can't see that being the problem either as one side would have to move "faster" or "slower" to produce the desired effect!

Please let me know!


Thanks!
A.

allan
11-02-2015, 07:44 PM
Try pressing against the door while making prints.
Make sure the reg roller is not bind up.
Check that the fuser pressure is the same on both ends
Play with trailing edge color shift adjustment under > service mode > machine.

copytechman
11-02-2015, 09:19 PM
Try pressing against the door while making prints.
Make sure the reg roller is not bind up.
Check that the fuser pressure is the same on both ends
Play with trailing edge color shift adjustment under > service mode > machine.

Thanks for the above:
Fuser swapped with a new unit and no change, I will check the reg roller, and will try pressing on the door to see what that may do, I did check that trailing edge colour shift adjustment but it didnt seem to apply to this problem.

Regards!
A.

EarthKmTech
11-02-2015, 10:22 PM
Good luck.

This is pretty much a standard feature on this engine. I'm pretty certain 2mm is within specification too.

blackcat4866
11-03-2015, 12:39 AM
How heavy is the media? I was working on a Canon the other day with similar paper skewing and color registration issues. I kept asking for some standard weight media, rather than the 275gsm glossy. At 250gsm it fed the paper straight and the colors registered properly.

I had the same issue on an Oki C9800, and I could actually see the paper stall at the bite of the fuser, then transmit that hesitation to the color transfer. In this case 300gsm media, 25gsm heavier than specs. =^..^=

copytechman
11-03-2015, 11:46 AM
Good luck.

This is pretty much a standard feature on this engine. I'm pretty certain 2mm is within specification too.


Really? With the lead edge pretty much square and the trailing edge skewed like that?
Really? Wow.. Honestly hope thats not the case!

Regards!
A.

copytechman
11-03-2015, 11:51 AM
How heavy is the media? I was working on a Canon the other day with similar paper skewing and color registration issues. I kept asking for some standard weight media, rather than the 275gsm glossy. At 250gsm it fed the paper straight and the colors registered properly.

I had the same issue on an Oki C9800, and I could actually see the paper stall at the bite of the fuser, then transmit that hesitation to the color transfer. In this case 300gsm media, 25gsm heavier than specs. =^..^=

It was doing it on plain (20) and colour copy (28) media, cust said it was doing it across the board. Unfortunately its not really possible to watch the paper "flow" through this box, another thought.. what if the 2nd transfer doesnt make it all the way around or something like that, introducing a "twist" somehow. (precluding the fact that the machine is supposed to "know" how the 2nd transfer is sitting against the belt).

Regards.

A.

blackcat4866
11-03-2015, 11:36 PM
It was doing it on plain (20) and colour copy (28) media, cust said it was doing it across the board. Unfortunately its not really possible to watch the paper "flow" through this box, another thought.. what if the 2nd transfer doesnt make it all the way around or something like that, introducing a "twist" somehow. (precluding the fact that the machine is supposed to "know" how the 2nd transfer is sitting against the belt).

Regards.

A.

I suppose that if one of the 2nd transfer springs were missing you might get that effect. Or if the registration roller was lacking a spring. Or the fuser inlet guide(s) may be built up with toner. How many prints on the fuser? Also check that the the paper dust collector is not packed solid with paper dust. This group of machines has the interesting feature that the paper dust collector sits atop the registration sensor. So when the dust collector overflows, it overflows onto a reflective sensor. Nice, huh? There are actually two paper switches, one reflective & one photointerrupter that could benefit from regular cleaning.

If it were me, I would load up a 15% fill black original on ledger, then emergency stop the machine several times, to see at what stage the paper begins to skew, because the paper is skewing. =^..^=

copytechman
11-04-2015, 04:48 PM
I suppose that if one of the 2nd transfer springs were missing you might get that effect. Or if the registration roller was lacking a spring. Or the fuser inlet guide(s) may be built up with toner. How many prints on the fuser? Also check that the the paper dust collector is not packed solid with paper dust. This group of machines has the interesting feature that the paper dust collector sits atop the registration sensor. So when the dust collector overflows, it overflows onto a reflective sensor. Nice, huh? There are actually two paper switches, one reflective & one photointerrupter that could benefit from regular cleaning.

If it were me, I would load up a 15% fill black original on ledger, then emergency stop the machine several times, to see at what stage the paper begins to skew, because the paper is skewing. =^..^=

Tried with a brand new fuser, machine only has about 400k total on it. I'll be checking the door and the other things when I return, also latest firmware just in case. Will also check the paper dust remover (cleaned it last time I was there). I was thinking of running a 50% yellow and doing an engine stop just after paper left the belt to verify image is square to the itb and then build from there as well. Image "should" be square on the belt if its paper skewing I would think.

Thanks for all the input, will keep all updated!

A.

MVPunisher
11-04-2015, 08:32 PM
I once battled this exact problem on a C654. I must have replaced everything you could possibly consider. I never resolved it because the machine was moved to a new location and the skew wasnt as big of a deal in the new location. The next step was going to be the MFP board. Which sounds ridiculous but the guy on tech support had told me it did fix it for one other person. The image does process there so not that far fetched. Good luck and let me know if it fixes it.

copytechman
11-05-2015, 12:44 PM
I once battled this exact problem on a C654. I must have replaced everything you could possibly consider. I never resolved it because the machine was moved to a new location and the skew wasnt as big of a deal in the new location. The next step was going to be the MFP board. Which sounds ridiculous but the guy on tech support had told me it did fix it for one other person. The image does process there so not that far fetched. Good luck and let me know if it fixes it.

That is one my options as well, (diagnostic board). Will keep all posted!

Thanks!
A.

fishleg
11-11-2015, 07:59 AM
C452, C451, C450, C350 seen all with exact same problem. Some I swapped out registration, some where the actual tray believe it or not. First thing I do is load all tray with A3 including bypass and see if the skew is different between them as sometimes its before the registration.

Sent from my D6603 using Tapatalk

copytechman
11-16-2015, 12:30 AM
C452, C451, C450, C350 seen all with exact same problem. Some I swapped out registration, some where the actual tray believe it or not. First thing I do is load all tray with A3 including bypass and see if the skew is different between them as sometimes its before the registration.

Sent from my D6603 using Tapatalk

Crazy... some with trays, some with mfp board, gotta love KM!

Regards!
A.

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