RM8401Dometic fridge no display on control panel

[multiwick]

I am having problems with my Dometic RMS8401. Fridge not working on battery, mains or gas. I have 240v & 12v at the back of the fridge. Front control panel does not appear to be working. Where else can I test for voltage  and how can I diagnose the fault 

[Labby]

If you  look back on the posts on here to March 14  Steve Hill had the same problem with his RM8501 and the information there could be helpful to you in finding the fault.