I've done quite a bit of searching for a remedy to this problem. Most FAQs I've run into have said this is due to a defective drum. The line is same length as the transfer roller so I'm guessing that the line is from the roller (there are also faint lines on the transfer roller). It is very hard material (can be scratched off). The longer you leave the cartridge in the printer (even not being used) , the more lines appear. I just cleaned about 10 off of the old cartridge. This started happening just after I installed a maintenance kit in the printer. I wish I had the old parts but I sent them back for a core charge and the next day the lines appeared. I just replaced the toner cartridge and this is a pic of the new cartridge after one hour in the printer (in sleep mode). Any suggestions?
