Streaks in cyan

Our Igen4 is having an issue with printing a smooth image of a 4 color build on a back panel of cover stock. We print two different colored builds on cover stock, one is yellow, the other dark blue. Each order may contain several of the blue and the rest yellow. It prints good for a while (10 to 15 thousand sheets), then suddenly has streaks in the blue. New grids, wires, pr belt, fuser roll, no change. Only thing that seems to work is dumping the cyan toner/developer and vacuum the cyan station out. Only xerox is allowed to do this and they always change almost every part before doing this last. One tech said it was "undertoning", made some changes in diagnostics (the one only they can only use) and it worked for about 100 sheets. They seemed stumped, don't feel that they should have to dump and clean the developer/toner at all. Any suggestions?

 

think maybe they need to change the developer station itself?

 

yeah, maybe they should try switching the cyan developer housing with another to see if the developer housing itself is having a problem.
did this just start happening recently? and are you sure the streaking only occurs in cyan?

 

Well, after trying different toner settings the tech finally dumped and cleaned the housing, replaced developer. It works fine now. The coverage is 8.5x11 area on the back panel. Never seems to have trouble with any of the other colors. This machine is running 50,000+ cover per week, running 16 hours a day. When asked the tech says that the developer never needs to be changed, but that seems hard to believe. The did swap the housing with our other machine but still had problems. Right now the cleaning seems to fix it short term but they are still trying to figure it out. I don't know what type of volume is normal for these machines but it could be be that we are just maxing them out. We change fuser rolls every nine working days or 250,000 impressions. PR belts at 500,000.

 

Has your tech re calibrated the TC sensor using the fresh developer method? I am finding across the machines I look after over here in the UK that the sensor reading drifts overtime. It's the same sensor (TDK) that is used in the DC8000/6060 and Chamonix. The sensor only has to be out by 0.5% to cause IQ issues. The carrier system is a huge benefit over the iGen3 but still can struggle overtime if running high area coverage.

I run developers to approx 5mill HFSI counts in a graphic arts enviroment were I then replace the dev and re calibrate the TC Sensor.

 

Take The Two Rollers Out And Give The Developer Unit A Hover Out There Might Be Developer Clogged Up Either Side Of Where The Rolls Are.
And Look Under The Developer Unit Nearest The Front You Will See A Large Bolt Unscrew It And Be Careful As Some Dev Comes Flying Out But Give The White And Black Circle A Clean This Is A Sensor And Sometimes That Does Need Cleaning With An Alcohol Swab.

 

We seem to have had this problem and though all your steps are in line with common trouble shooting we tried cleaning the glass and the mirrior. Believe it our not it worked. This really seems to solve most image or banding issues for us.
jg

 

These sensors are not used on an iGen4 only on an iGen3. The sensors used are TDK sensors are smaller and common with XC1000/800 and 8000 family

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Mark