C451 color registration prob

**mattguthrie** · 11-08-2016

Good Morning,

I have a C451 with an issue I've not seen before. I have attached a pic. The registration at the top of the page is fine; toward the bottom it starts to spread out. I've changed the transfer belt and roller. Also, I looked in the belt cave and checked all of the couplings that attach to the belt assembly.
I thank all in advance for their insight.

image.jpg

**mo0651** · 11-08-2016

Does it happen on single copies? or Multi copy runs? I am assuming the top of the page is the lead edge.

**mattguthrie** · 11-08-2016

Originally Posted by mo0651

Does it happen on single copies? or Multi copy runs? I am assuming the top of the page is the lead edge.

Thanks for the quick reply. The top IS NOT the lead edge.The right side is the lead edge.The problem is intermittent but seems to happen only on multi-page jobs.
Also, the orange looking lines in the pic are where the magenta and yellow have aligned together perfectly but are still out of registration with the whole image. Looking at the bottom, I can see the black line where everything should register. Above the line, is the M/Y line but the C line is BELOW. Certainly not a belt problem I believe. Why do M and Y register together but not with C? Printer Control Board?

**Synthohol** · 11-08-2016

Clean your 2 registration windows first then maybe try a skew correction reset.
Do you have a p21 as well?

**mattguthrie** · 11-08-2016

Originally Posted by Synthohol

Clean your 2 registration windows first then maybe try a skew correction reset.
Do you have a p21 as well?

Thanks for the reply Synthohol. I'm pretty sure I cleaned them when replacing the belt but have not tried a skew correction reset. I'm on my way back to the customer's location so will do a reset when I arrive. There are no P codes.

**Albonline** · 11-08-2016

Originally Posted by mattguthrie

Thanks for the reply Synthohol. I'm pretty sure I cleaned them when replacing the belt but have not tried a skew correction reset. I'm on my way back to the customer's location so will do a reset when I arrive. There are no P codes.

run 11by 17 gradation test patterns at 255 watch what happens. this is probably from an hv arch flipping out the led array. lots of different causes, usually just needs a really good cleaning and to be calibrated.

**mattguthrie** · 11-09-2016

Originally Posted by Albonline

run 11by 17 gradation test patterns at 255 watch what happens. this is probably from an hv arch flipping out the led array. lots of different causes, usually just needs a really good cleaning and to be calibrated.

Thanks Albonline. Your solution seems to be what cured the problem. I returned to the customer yesterday morning as I had said I was going to do in an earlier post. Upon arriving, the customer was super sweet and proceeded to tell me that she had run over 2000 pages with no problem. The day before, in order the check the belt drive assembly, I had to swing the cage open. You would not believe how much dust was behind it. Well, you work on copiers so I'm sure you do. After cleaning, checking the belt drive, wast toner drive, etc., and not seeing anything obvious, I put everything back together. Nothing else was done, not even a calibration. Clear as mud? Thanks for everyone's input. It's good to know my colleagues have my back.