Konica minolta c452 color registration off

I have a c452 with color reg. failing after a couple of days and then I do stabilization and it comes back.
Units that were replaced were c,m,y, image units.
Cleaned the id sensor array and performed stabilization.
Held for two days then threw reg. off again.
I manually adj. registration then defaulted back after call back.
If you have any suggestions on what course of action repaired your machines with this symptom please forward any suggestions. My next course of action will be swapping transfer unit with a working one and then the sensor array.
Thanks