Re: Light patches on Minolta Di620 duplex copies...

[Copycat2]

Hello everyone,

I'm getting light patches on all duplex copies on our Minolta Di620 B&W engine. This problem is especially prevalent on letter-sized (8.5"x11") double-sided B&W copies. It looks as though the paper passing through the imaging section of the B&W print engine is not making full contact with the drum. As all fuser parts and rollers have been replaced, is it possible that this could be either a vacuum issue or a transport problem? I also thought that the copy paper could be the culprit but I've opened another box and the same problem persisted. The light patched areas are on one side of the paper and seem to originate in the same general area of the copies. Both fuser rollers (upper and lower) have just been replaced with OEM parts and the Web Pressure Roller and Web Roller have also just been replaced. Would increasing the pressure of the two Roller Pressure Springs on the Lower Fusing Roller help alleviate the appearances of the light patches on the copies? I don't know what the proper factory pressure settings are for these springs. I'm afraid that if I torque down the two Roller Pressure Springs, I might damage the components in the fuser unit.

Thanks for your help everyone. I welcome your comments and advice on this one.

[cobiray]

Have you replaced the transfer and separation coronas? How about the charge grids and combs? Are the light areas patches or streaks? If they are streaks, check the corona cleaners to see if they are stalled in the image area. Also the transfer corona may be broken.

Also, there is no adjustment on the fuser pressure screws. The proper setting for the screws is all the way tight and there is no nip adjustment either. If they aren't all the way tight, it could be the problem, especially if the toner rubs off the paper. If the problem occurred after the fuser rebuild, double check your work before tearing into the rest of the machine. Hope this helps.

[Anrath]

Most likely its time for new T+S wires. Be sure to change the end blocks too, the little posts get corroded and you lose connectivity.

[DUKEY]

Yikes this is old school machine, but a work horse! i used to take care of 3 machines all micropressed together, there r 2 little, i mean little spacers on the transfer plate right before the corona, like little spots, they make different sizes, sounds like u have to much space between drum and plate, and if u wonder why first side is ok and not 2nd is 1st goes through fuser,and coats with oil and 2nd needs more transfer power.thats why decreasing space will help with transfer of image..