Printer and Photocopier Troubleshooting and Repair Collection : Previous copy doesn't erase from drum   
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Previous copy doesn't erase from drum

"I recently purchased a Mita DC-111 copy machine, and I finally it to make copies, now I have on big problem. When I do more than one copy, the drum doesn't fully erase itself, thus leaving ghosted images on the remaining copies that are made. I don't know much about copiers, and I really just lucked into getting it to actually make copies. Any help would be appreciated.

(From: Jeff Roberts (jroberts@axionet.com).)

Make sure it is the drum that is not cleaning by measuring the distance between the origional image and the ghost image on the page. that distance will be the circumference of the drum if that is the cause. The drum assembly should come out as a unit. Take it out and make shure to quickly remove the drum from the unit and put it in a dark place so that it doesn't become light shocked. then look for a blade of some sort, it may be neoprene or rubber. it is usually on a actuater assembly that can push it out to make contact with the drum and then retract it back (possibly a solenoid/cam) this blade does the cleaning by scraping the excess off the drum. If it is hard or brittle it will have to be replaced but cleaning it with a 70% solution of rubbing alcohol may be enough. After cleaning it rub some toner along the edge to re-lubricate it and reassemble and try that. Also check that the drum unit is not clogged up, the waste toner goes somewhere and if it uses a sump and the sump is full then it will ghost no matter how clean the blade is.

(From: Vance Harlow (musk@aol.com).)

On copy machines and laser printers with long life drums (ones where toner can be refilled without replacing the whole drum assembly) the wiper blade will usually fail long before the drum does on machines that are not used frequently or used to print one or two copies at at time. If the service department is not aware of the problem, or the manufacturer doesn't supply the blade as a separate part, you'll usually end up getting stuck for a whole new drum assembly when all that's needed is a wiper blade (this is the rubber or plastic blade that bears on the image drum, not the felt wand, BTW).

Usually the clue will be that the first few copies are bad, but then quality improves. If that's what's happening, usually replacing just the wiper blade will cure it.

Since the blade costs only $10 or so, it can be worth giving it a try before replacing the drum assembly. This has worked on both my Canon 1010 copier and various OKI and GCC laser printers.

Finding the blade can take some doing - when I called the local Canon distributor, they couldn't give find a part number, even though I'd bought a couple years earlier and knew it existed as a replacement part. Luckily, one the the service techs was able to dig up the number. OK doesn't list them at all - they only sell the the whole assembly. But you can get the blades for most laser printers, and some copiers, from American Ribbon and Toner or Computer Friends. Since the drum assembly on the old Okis like the 400 and 800 series, and the GCC/Mac versions lists for $250 or so, one frequently runs into them with bad drums for $0-25. I've revived a half dozen of them simply by replacing the blade - knowing this trick is like having a free source of laser printers! the OKI blade pops right in with only minor disassembly; the Canon is a bit more trouble.

Computer Friends also has a teflon wax for reconditioning drums - they claim it will protect the coating, fill in small scratches and treble the life of a throw away drum, and vastly prolong the life of long life drums. I've tried it so far only on an old 1010 drum, with mixed results so far (worked great at first, but now copies are getting dirty - don't know if it's the wax acting up, the drum going despite the wax, or other problems. They also sell the Oki drums for about $40, and drums for many other printers but not copiers.

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