Im posting this message with a lot less hair than I had an hour ago! I have a customer with a Canon IR2020i that is producing faint splotchy prints(almost a tree bark) on the image area on about 1/3 of the back of an 81/2 x 11 page. Almost looks like the transfer roller is not coming in contact with the drum on the back side. I've done all the usual things. New transfer roller, springs and bushings. Stopped copy half way through and image is fine on drum. I even checked hinges on door. Didn't progressively happen but was all at once according to customer. Almost seems like a voltage or bad ground issue but checked that and everything seems fine. Here's the kicker. If i run a double-sided copy the second side is fine. Has anybody experienced this out in the field? Even with my many years of Canon experience these machines still manage to "humble" me on occasion. Thanks in advance.
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You answered the question when you said the 2nd side is fine. You've got bad paper. High moisture content in it. Once it passes thru the fuser on the 1st side it takes the moisture out and the 2nd side is fine. Get a nice fresh ream and I think you'll solve your problem. -
Check the Ribbon Cable between the HVT and the DC Controller.**Knowledge is time consuming, exhausting and costly for a trained Tech.**
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Brian
Thanks for responding. Thought of that but if I take a single-sided copy and run it back through the bypass tray for the other side i get the same faded result (tried a fresh ream just to make sure). Thanks again...Comment
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Do they go bad or just lose their connection?Comment
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Well guys I tried all of the above with no success. Talked to other Canon dealers and they've never seen this problem (my luck). Definetally a transfer voltage problem. When I register paper as thick stock or heavy it darkens the light areas but print is still fuzzy from the tree bark its putting on the page down the back side of the copy. It happens with everything (copy, faxes, prints and reports). Its almost like the transfer is leaking voltage because when i do double-sided the second side is fine. Any more help would be appreciated. Thanks.Comment
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transfer roller bias
tb.JPG
A negative bias, sheet-to-sheet bias, or positive bias is applied to the transfer charging roller according to the type of sequence.
The negative bias is applied at the prescribed timing to moves the toner from the transfer charging roller to the photosensitive drum for cleaning.
The sheet-to-sheet bias is lower than that applied during printing and it is applied at the prescribed timing to prevent the toner remaining on the photosensitive drum
from adhering to the transfer charging roller.
The positive bias is applied to transfer toner images from the photosensitive drum to paper.**Knowledge is time consuming, exhausting and costly for a trained Tech.**Comment
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