If you: "shut off everything for a couple of days and then turn back on to have
everything works for about 5 to 6 weeks and then refrigerator section
stop getting cold again."
Then it is likely the defrost system.
The defrost system is located behind the unit back panel, and its function is to keep condenser coils free from frost.
the defrost system is not working fine, the condenser will go under
stress and the unit will produce insufficient cooling, particularly on
high temperature conditions.
If it is a defrost system problem leaving unit to defrost completely will fix the problem for few weeks, then it will restart in consequence of the missing defrost function, and of ice on the condenser coil.
The defrost system comprises of an heating coil, a thermostat, a fan.
Heating coil and thermostat are tested using a multimeter to read Ohms on the part contacts, the fan is testing energizing it.
If you want a quote on repair you can contact the phone number listed on the user manual.Here parts and diagrams for the model in title.