C6501 wavy paper

**mrwho** · 12-06-2012

I'm getting this on a C6501, paper gets one - sometimes two or three even - wave near the trailing edge of the paper.

It happens from any tray, both face up and face down, and it happens about 80% of the time. Changing motors and clutches around made no difference whatsoever, neither cleaning the transport rollers. The few times I jammed the machine on purpose as the paper entered the fusing unit, the paper was never buckled, so I'm leaning towards the fusing unit, although I've never seen a machine do this before.

It happens with A4 paper 80gsm, as the pictures show (face up and face down, from either finisher tray).

**eifling** · 12-06-2012

You check the one way gears in the fusing unit? I have that happen when they go bad or the shaft they are on starts to get worn. That or the bearings in the lower fuser roller.

**HoonBoy** · 12-06-2012

Could be the exit roller on the fusing unit (rubber rollers on shaft could be worn or oneway not working properly), or else the decurler roller(and it's ball bearings).

**TxTech** · 12-06-2012

Does this have the basic model finisher on it? If so, replace the conveyance rollers in it. have had this happen on 2 machines now.

**Mick01** · 12-06-2012

Hi,
I too am leaning towards a finisher issue. Take the finisher off and see if this resolves the problem. The main culprit is the drive roller just after the punch unit.
Kind Regards.

**mrwho** · 12-07-2012

Thank you all for the tips.

I've ruled out the finisher (for now) because when the paper gets out face up, the defect appears near the end of the paper, but if it comes out face down, it appears near the beginning of the paper (as you can see on the attached photos) - this leads me to think the problem happens before the reverse unit.

For now I'll take the hint that it must be the fusing unit and so I'm ordering the parts to rebuild it.

Thanks!

**methogod** · 12-07-2012

Does your machine run alot of duplex post cards or coated stock?
How many clicks does the machine have on it?

I would also test with 80# gloss from mohawk, We would get a small ripple that looks a lot like your issue as the exit decurling is failing. If the 80# gloss is sometimes very thin and inconstant Which can sometimes not run well no matter what you do, but i would eliminate the above issues. First step is verify paper settings are correct, Coated stock should be printed from the LCT or PF UNIT, make sure the paper is set to Gloss Offset and the correct weights. Make sure nothing has been changed in the adjustments (that should not be).

When we run post cards we have to open the fuser exit pressure conveyance, then close it from anything lighter, back to the center, and very light all the way on. If you not sure what i am talking about i can upload some images.

Could be one-ways on the fuser, but you can clean them and see if it goes away (if it does replacement them), other things to check are loose screws on the FUSER. LOCKtite is your best friend, especially on the back side of the fuser. I have wasted a few fuser belts because the pressure spring screw comes loose on the back or the front, causing odd problems.

If you can eliminate the fuser, i would clean with De-ink all the grey rollers from the LOOP Roller, Registration Roller, as well as the just where the page stop and flips in the ADU.

The last thing would be to pull the exit unit, and check the bearings, and see how worn the exit decurling roller is. If it doesn't feel right its probably time to change it, life is 1million, but with heavy stock and coated paper it maybe 700K if your lucky.

Quirky stuff we have seen is also failure of the FIXING LIMITER (bottom of fuser 65AA53651).

Try these things and see if it helps at all.

kahdgar · 12-07-2012

Hi we had this problem on our C6500. We found that we had to trick the machine because the fusing temperature was the issue. We set the paper to plain and set the weight to the lowest possible so the fusing temp would change. For us the lowest weight was 64-74gm2

**newmang** · 12-07-2012

We had this and found some information regarding changing the Fuser Seperating Plate. This has a 300K life on the C6000 but is not quoted on the earlier machines. We have now checked a few and they are worn and it does fix the fault. Fit the C6000 part to earlier machines as well.
A1DU R74H 00 Fusing Separating Plate