If your refrigerator/freezer stops running and cooling and will only work after it is unplugged then plugged back in, replacing the thermal fuse (thermistor) may be the answer to your problem. Here's how to check the thermal fuse to see if it needs replacing. The problem particularly affects Samsung units with model numbers that start with RB followed by four numbers, for example, RB1955VQ or RB2155SH. This one is model RB1955VQ. The best and most complete do-it-yourself instructions on the Internet! For more helpful how-tos, visit the doityourselfstan YouTube channel @doityourselfstan or www.homefrontstan.com.
