How should i fix it... ? many thanks sir ...
- transfer belt .. OK
- Drum catridge ... OK
- not show error code
While the Status of the Transfer or Drum say they are OK, that appears to be very much not the case.
The status will only tell you how much life is left, it does not show when something is damaged. It looks like someone fed something through the machine that they should not have (whiteout or a label that came off the stock ) and damaged the belt/drum.
Take out the parts and inspect them individually to find the one with something noticeable on the roller.
change drum cartridge ? or Roller Charge ?
but i try to do color regis (diagnostic) .. all mode OK except the Rough Skew Set up not pass and very long time to regis .......
You are the one who has the device, find the thing that is physically damaged and replace it.
If you can't find a part that is damaged you will need to pay someone who can.