Kitchen Large Electric Appliances - Frig Temperature control problem

GE TBX22PCSNLWW. Initial problem was running all the time with temps going up to unacceptable level in frig and freeze. THINK issue was clogged defrost drain. Cools good. Now frig temp cold but inconsistent. Turned temp control setting down (3...5 initial setting 9 coldest) last night and temp this AM 32F. 20 plus year old machine. Could it be bad temp controller or problem with condenser that makes system too cold? Thanks.

I have adjusted thermsotat settings (tiny screw like eyeglass frames have) successfully before, and had no call backs after wards, from situations like yours. One became so sensitive that the temp dial had to be turned down to about a .5 setting (yes, between 0 and 1 on the dial) in order to have it get to the point that it would not run all the time and freeze out the refrig. compartment - and that is when I decided enough was enough and recalibrated the stat mounted from the ceiling of the refrigerator compartment. See if on your stat, you do not have some small hole that is on the bottom, and look up in there, with a mirror if you have to so you don't have to move too much food, and see if you don't have a slotted miniature screwhead up in there a ways.