Any and if so what error codes show?
Have you checked the diagnostic screens for info?
Turning off/back on........
Upper display goes DEAD/NO lights etc or fridge turns off/on?
*Loss of 12VDC either:
TO Fridge (10.5VDC to 15.4VDC operating range---below/above fridge shuts down)
To Upper display (harness connections/wiring on lower to upper boards)
Upper display optical board fault
Depending on YOUR fridge S/N determines which diagnostic mode is used
Pg 46 or pg 49
Check for 'Live' Inputs and 'Fault' history
https://www.thetford.com/wp-content/...68C_022707.pdf