I have a GE side by side that runs great for 8 hrs.or so,then shuts off and sometimes goes into defrost mode,but I have to tap on the knob on the back wall of the fridge so it will start up again. A service man charged me $50 to tell me I need a cold control.The part is discontinued and I can't afford a new fridge. Could it be the cap. Tube? Please suggest something.

SOURCE: defrost does not stop

Yes the timer stops when the cold control cyles off (satisfied) i have also has plenty of your exact model have faulty cold control cycling off when the fridge is very warm +40) both are relatively inexpensive and you will save a ton off a retail repair.

SOURCE: fridge problem

you have a defrostion issue reed to remove the back panel in the freezer behind this panel is the evaperator coil needs to be melted down because it is full of ice and frost, ahair drier will work well,put several towells down under the bottom of the evaperator to catch water runoff, after defrosting the coil inspect the defrost heater or heaters some of these can have one or two heaters the heaters are located behind metal gaurds in the evaperator if either of the heaters are bad (both)need to be replaced, if they show good then bad defrost timer or bad defrost termination thermastat wiring diagram behind frount bottom grill

SOURCE: GE side by side fridge not cooling, can't adjust temp control

Most likely it's not defrosting, many GE fridges need new defrost heaters every couple of years.

SOURCE: GE Side by Side Not cooling/freezing

sounds like defrost problem. remove back lower panel in freezer. defrost all ice on coils, this will fix problem temporaily. I`m looking for the tech sheet to test system.

SOURCE: My GE fridge is not defrosting the coils in the back. What's up?

if u have frost build up in the freezer it will affect the temperature
and it needs to defrost
problems could be
defrost timer.
thermostat.
terminator.
heater s.
unit problems (unlikely) if even frost coating.