Freezer and refrigerator are at 44 and 47 degrees and common causes for this all check out fine. Evap fan is working and also condenser fan motor. Compressor turn on ok. No frost on the coils. Air is circulating as you can feel if in freezer vents and vents in fridge but it is just not very cold. Minimal dust on coils. Could it be stuck in defrost mode? If so, how would I check for this. We bought the fridge used in 2009 and assume it is over 10 years old. Could it just be time to have more freon put in? Is there anyway to determine if that is what is needed? Recharging the system with freon is probably not something I would want to try myself. Thanks for any help.