Hi everyone. I have a call on a MPC4500 that I have tried to fix twice this week. Not sure what to do next. The samples they show me are color prints, single sided, printed side is perfect, backside has a heavy background on it about 3 or 4 inches wide that goes edge to edge at the lead edge on LEF 8.5 x 11 white paper. I replaced the transfer cleaner unit and have cleaned the transfer roller which dosent seem to be dirty at all. It hasent done it yet for me, seems to be random. The background seems to have a magenta and black tinge to it. Any one seen this before? Thank you for any help on this.
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Re: Dirty backside of color prints
make sure that the paper path is clean, encountered this problem if the machine copy continuously dirt will accumulate on top of the transfer roller. you have to replace the ITB cleaner.Nobody is perfect.. -
Re: Dirty backside of color prints
when it does happen do they have examples, if the machine jammed or something and they removed the jam but got toner from the itb all over the ptr it could be dirty for a while, the toner has to come from the itb at some point to get the ptr side for the back of the sheet. You did the itb cleaning unit so i guess i would check the page/pm count on the ptr I hardly ever replace them on this model but they do go out, id also check for voltage issues, i had a machine with a burned out surge protector on it start making lines on fronts and back of pages randomly due to voltage drops/surge. If the ptr is over 240k id just try a new one and see what happens, and then i would question them on what happens when it does do this is any of the orginal image missing on page that caused extra toner to roll on the ptr, or jam issues they are removing etc.Comment
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Re: Dirty backside of color prints
This wouldn't be a heavy paper issue? I've run into that a few times where people are trying to run heavy or weird paper on normal paper settings that causes problems on the back side of copies or prints from unfused toner buildup in the fusing unit.
Also, most of the color machines that I work on have a maximum paper weight of 67 or 68 pound card stock, and the people I've seen trying to run 100 pound card stock eventually always encounter woe kind of like this.
But this sometimes this causes defects on the front side of the prints too, so maybe not.
Still, something to check out if time permits.Comment
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Re: Dirty backside of color prints
Thanks for the comments everyone. I had allready replaced the transfer cleaning unit but still happened. I did check the jam log and the machine rarely jams and no jam during the period that the problem happened. They run about 20 k a month and most of that is color copies on sef letter colored paper. They have not seen the problem on the colored paper, only white 20lb lef copies and prints. Both black and color. It has to be a transfer issue, right? Today I replaced the transfer belt and cleaned all the rolers and connections. I will see what happens. I will try the tr roller if this dosent work.Comment
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Re: Dirty backside of color prints
It sounds quite likely that the transfer roller is bad. I have always had terrible luck whenever I tried cleaning worn or overly contaminated transfer rollers, starting back in the day when copiers required coated paper, so a new transfer/separation unit is probably in order.Comment
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Re: Dirty backside of color prints
This cust just called with same problem. I will change the paper transfer roller to see if that helps but I am wondering where the excess toner is coming from that is aparently getting all over the roller in the first place. Any other ideas?Comment
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Re: Dirty backside of color prints
Does it look like its leaking Dev from the Dev units as the mgt and blk dev is used the most I would look at the copy count for them and change if over the PM cant be Image transfer Belt related as it would be on the printed side of the copies.Comment
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Re: Dirty backside of color prints
I will be there this morning and will check them. Im still going to change the tr roller any way. Its tough to know when its fixed because it only spits out one of these bad copies randomly. In this case its been working for several thousand copies.Comment
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Re: Dirty backside of color prints
Did you check the fuser?Comment
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Re: Dirty backside of color prints
The dev and the dev units are well within thier life span but it did seem like it could have something to do with the dev so I replaced the Black Dev and cleaned the dev unit. Maybe the bias was shorting out? So far its working but it has taken thousands of copies before it happens so I will wait and see. I did check out the fuser, it was fine.Comment
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Re: Dirty backside of color prints
Hi there!
Had this issue a few times. Changed the transfer-cl-unit & transfer-roller. Worked for a couple of day's, then it was the same. After changing the complete dv-unit('s), the problem was solved. Coleague of mine had the same problem, and the dev-unit was bad. He changed the complete unit - OK.
Greetings...Comment
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