C500 black dusting edge to edge

[Operator Error]

I have a C500 thats kicking my but I need some help guys. Black dusting on edge to egde copies and prints. Not as noticable on normal paper but really shows up on gloss and coated stuff. Here's a list of troubleshooting steps taken also its hard to see on halftones. I performed a 600k pm with all new units cleaning, intermediate assembly, dev units nothing was missed 100 and 200k was performed. Our DSM came out advised me to have the UFR, web, and install the C6500 intermediate assembly mod nothing worked. Has anybody come across this issue I'm stumped please any suggestions would be very much appreciated. Thanks

• Cleaned entire image process unit
• Inspected drums and dev also cleaned all colors
• Replaced coronas
• Replaced HV1
• Troubleshooted with tech support
• checked drum potential and tdc outputs

[random]

This a low volume machine? 3 x gamma setups in a row and if this fails replace the k dev.

[Operator Error]

The machine is in a production print enviroment has close to 1 million clicks on it. I'll try your tip thanks

[Operator Error]

Its actually all the colors dots are being applied edge to edge background on everthing. thanks

[Rolandito]

Clean Write units glass.

[Itsthepaper]

Ouch!! I had goosebumps when I saw your post. I also had the same issue dusting edge to edge, It kicked my ass for a long time. It was the NVRAM, after I did everyhting, I MEAN EVERYTNING!! Finally I was able to use another C500 in the shop and started swapping out boards one by one, NVRAM nailed that sucker, that was 2 years ago and the C500 is still running good. If your a dealer get your Konicaminolta respresentative involved, they need to make sure it's the NVRAM anyways.