8050 with streaks front to back

[laserman06]

I have an 8050 that is having streaking issues. The streaks run from front to rear. I only have them show up when the customer prints a light gray scale. When I run my halftone test print at 90 You can see them clearly.

I have replaced both the drum and K developer assy. I am beginning to think that it is in the drive of the K drum/developer.

I have attached a sample of the defect. This had to happen now. Customer is replacing machine with a C6500 in April.

Have you ever had one of those weeks. Nothing seems to go right.

[random]

This happens when using thick card (I assume your are printing on heavy stock) and the lead edge of the paper hits the 2nd transfer and belt with a thud and sends a shudder thru the belt to the black drum.

The distance from the lead edge to your first line will be the distance from the 2nd transfer to the 1st transfer of the black.

How to get around this? Tell your customer to put a color dot on the page somewhere and print the job in color and you can credit them. In full color mode all transfer rollers are out and the belt tension is higher. You may still see some shudder but usually this solves it.

Does c6500 do this? Yes it does, however there is special firmware where the customer can select special black mode that activates all transfer rollers in B&W mode.

[laserman06]

This also does this on 20lb paper. When you use 8.5 x 11 paper the first streak is almost to the trail edge. Do you think that it is the same thing?

[random]

I would measure it to see if it is in the same place. The test would be to see if it does it in color. Im in a metric world so 20lb doesn't mean much to me but I would be surprised if it is on normal printer paper.

If it does I would be looking at the belt springs, or even rebuild the belt. Take your print and match it up to the belt. Match the lead edge up to the contact point of the 2nd transfer and see where the blur is in relation to the 1st transfer for black.

If this appears in color mode then I would be looking at doing that stupid fuser line speed adjustment. If it has a finisher take it off and test again. If the fault is not seen with the finisher off I don't think you can do anything other than tell them not to use the finisher.