View Full Version : CQ Weird problem on KM1650 Light streak across page.

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09-09-2010, 05:46 PM
I just wanted to post this in case there is anybody as stupid as me out there.

I had a KM1650 that was giving me a light area across the middle of the page, lighter at the leading edge than the trailing edge. I knew it was in the scanner section because it didn't do it on self prints, just on copies. I cleaned the mirrors and lens, no help. Then I started swapping components from another machine. Swapped all components, including cables and boards. the only thing I didn't change out were the mirror units, because I had cleaned the mirrors, so it couldn't be that. Still no change. It seemed that it had to be something in the light path, but I couldn't see anything. Finally removed the top mirror, since you can't see it too well in the machine and sure enough there was what looked like and oil film on it right where the light area was. I don't know where it came from, and it didn't want to clean off, but I finally got it clean and the light streak was gone. I never had anything like that in 15 years of doing this.

Hope this can save someone else some troubleshooting time.

09-09-2010, 05:54 PM
It was more common on the machines with open fuser oil reservoirs. It's been quite a while.

99.9% alcohol will do a good job of cleaning those mirrors. To delay the effect, it helps to turn down the fixing temperature. It applies to the whole series: CS-1635, CS-1650, CS-2050, CS-2550, and possibly continuing onto the CS-180, CS-181, CS-220, CS-221 (the latest incarnation of the same platform). =^..^=

Ducttape n Glue
09-09-2010, 06:11 PM
Also, ozone can cause this same effect on mirrors. Check airflow, plugged filter or path, failed fan, up against the wall or some other thing.

09-09-2010, 07:11 PM
The pollution comes from the PULLEY FEED SHIFT (PL FIG. Ref No Exit 9 Section 19, 2C921040).

09-09-2010, 09:03 PM
I had this problem and using plain old tap water did it for me.

09-13-2010, 05:11 PM
I put tape over the two center holes on the left side of the optic block. It seems to happen more on the 2550 than on the 1650/2050, probably due to the higher fuser temps.

06-09-2011, 11:42 AM

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