Au contrere, Pierre.....Not THE problem, but certainly A problem as well. Has nothing to do with the door light, etc.
If I were you, I'd start with a proper voltage check at the rear where the cord connects to ascertain there is 240 volts from L1 to L2. Checking the breaker is not enough, for it won't reveal a loose or burned wire at the cord block.
A bad thermister can lead to temperature problems, which can lead to a blown thermal cutoff.