Samsung fridge not getting cooled

I have a Samsung rr82fdrs stand alone fridge without freezer.

Compressor stops after a few hours after i plug it in.

I have changed:

The inverter board

The two temp sensors inside

The fan inside

Messured the heater:

The resistance is at 470ohm

230/470=0,4893617021276596

230x0,4893617021276596 = 112

It should be at 110w so that seams to be right.

Compressor is getting first 170v on al 3.

When it is not cooling it is getting 50v

If i unplug and re plug the fridge star working again for a few hours.

So i do not think it is the compressor it self.

If it is something with the defrost i don't know how to search for the problem.