Intermittent calibration marks on copies

[outdoorkatie123]

Hi Anyone any idea how to solve the problem of intermittent calibration marks on primary transfer belt
replacing the belt solves the problem but would really like to repair the old belts as they are expensive to replace
The belt looks perfect and ive cleaned all the contacts
Thanks in advance for any advice

Joe

[jcg54]

Almost looks like the belt is either not cleaning itself ( I get this alot with the kyocera 406 models) or the belt isnt moving for some reason so possibly a gear issue?

[charge leak]

I don't think its a cleaning issue, I just replaced the cleaning blade on a faulty transfer belt, with a blade from a working belt, and I still have the calibration marks, which clear when I rotate the belt.