My Whirlpool refrigerator is not cooling things despite the fact I set up to the coolest position. I have already replaced the thermostat but that does not help. Any suggestions on what could be wrong which causes not to work properly?

Thanks,

Thanks, Denman for your reply and sorry for taking that long to reply with more info; had to deal with some other critical issues.

It is only the "fridge part" that is not cooling the juices, food, etc. The ice-maker/freezer works normally, and the compressor, fans all are okay. I checked the compressor, it is vibrating as normal. Since I replaced the old thermostat with a new one, could it be something else that causes the fridge not to work, maybe the "defrost Timer?

Thanks again,