I am beginning to despair. I have a Xerox WC7855 here that does "High Frequency Bands". Xerox also mentions this error in the service manual, but without showing an error solution. What I have already tried - unfortunately in each case without success:
1. replaced developer boxes and developer powder
2. replaced transfer belt unit
3. fuser unit replaced
4. replaced drums
5. 2nd BTR replaced
6. transfer belt cleaner replaced
7. replaced LPHs
8. replaced HVPS (Dev & BCR)
9. replaced Drum/Developer Drive Assembly
Does anyone have any tips for me? The machine has about 500,000 pages on the counter. Attached also three test prints. It appears that the error occurs especially with Black and Cyan.
