When your old capillary thermostat goes bad inside your refrigerator, you can either replace it with another analog thermostat or with a digital one from ebay for instance: the Meihang Technology MH1230A temperature controller.
Step 1: Remove Old Thermostat
Unscrew the thermostat block on the inside of the refrigerator.
On the bottom you will find a lid with 2-3 latches on one side that can be opened by hand, and one on the other that can be pried open with a small screwdriver.
Step 2: Connect the Temperature Controller
When the brown and black wires are connected the compressor turns on.
Brown and blue used to power the light bulb after opening the fridge door.
White and brown seemed to be the same, so I put them together.
Step 3: Improve Energy Efficiency
Convert a Standard Minifridge into a High Efficiency Refrigerator - Part 1/2
How to insulate a refrigerator