What can I do before calling a repairman. The refrigerator part is cool but not cold.

I bet your coils under the refrigerator are packed with dirt as well as the fan blades. Unplug unit. Pull out from wall and carefully remove rear cover by first removing screws (1/4" nut-driver needed most of the time). Do not damage this cover. Then wash out coils, but first blow out with air and vacuum up dust. You want to spray fan blades and coils with a good spray cleaner to cut grease and dirt, then spray with nozzle to wash off dirt. Vacuum up with wet-vac. Make sure to keep water out of motor. You can easily remove blade by removing one nut on motor shaft. It's just a stamped metal blade-just do not bend it. Then put everything back together and you have a new refrigerator. Pay attention to put cover back like you found it-it routes the airflow through the coils. This will cure your problem unless you have ruined the compressor by letting it stay dirty. Dirt is the number one cause of all refrigeration and AC problems and failures. DrTom4444