I'm looking for suggestions as to what might be wrong with my 1988 GE refrigerator, model #TBX18KKB. The refrigerator is not cooling properly. The freezer section seems to be about the correct temperature for a refrigerator and the refrigerator section is cool but not cold. The coils are clean and the fan in the bottom rear seems to be running fine. I would appreciate suggestions. For a refrigerator this old, it does not seem worthwhile to hire a repairman, but I hate to throw it out without first seeking some suggestions. Thanks.