fridge and freezer warm - read our story - KBFS25EWMS2

We are stumped, my brother is an appliance repairman with 40+ years under his belt, and this one has him totally without any advice on how to fix this fridge.

Refrigerator and freezer will not cool.

This initially started as a slow increase in temperature over a week in the freezer. We vacuumed the coils on the bottom of the unit. This had no effect. The compressor fan blades were broken and these were replaced; fan motor is running fine. At that time we also added refrigerant to the system, although very little was needed. This also had no effect. The refrigerator/freezer continued to get warm and would not chill. Next, we replaced capacitor and compressor relay and this had no effect either. We opened up the freezer compartment and exposed the coils – the coils had no frost. Thinking the heating coil may not be turning off, we disconnected the heater. Still no frost buildup. The fan in the freezer compartment is running. Also, the compressor is running, although it gets very hot due to the unit not shutting off (due to warm fridge/freezer).

Looking for other suggestions to try. Even though the compressor is running, could it be faulty?

We actually love this fridge - and miss it as the loaner my brother gave us to use sucks! top freezer unit - yuck.