Here are your parts
Replacement parts for General Electric TCS18PADBRBS Refrigerator | AppliancePartsPros.com

Note: I will not be able to tech find info on this unit as GE likes to keep it a secret. Look on the back and under the unit to see if they put the wiring diagram there.

If compressor is warm and is humming and/or you can feel it vibrating it is probably OK.

Clean/check the condenser coils and fan.

Check that the evaporator fan in the freezer is running, it is required to push cold air into the fresh food section.

Put a thermometer in the freezer, it should be around 0 degrees F.
If it is lets say at 25 then everything in it will stay frozen but you will notice the difference in the fresh food section.

Check that someone has not changer the fresh food setting. Looks like this is just a mechanical damper which regulates the amount of air allowed into the fresh food section.

If the compressor is cycling more often than normal you may have a thermostat problem.

If it is cycling less often you may have a defrost or low freon problem.

Pull the evaporator coil cover in the freezer so you can inspect the coils.
If heavily frosted/iced over you have a defrost problem.
If there is only frost in one area, usually where the freon enters the coils you probably have a low freon problem.