Refrigerator temp reads 57 but freezes everything changed main board and then the correct temp was registering then went back to 57 after about an hour

Its either a bad defrost timer not kicking on, bad main control board or the temp switch. Sorry not much help but the only way to really tell is check with a ohlm meteor and eliminate each part.

I think your thermostat is defect. Not registering the correct temperature. dial in a higher temp for the time being, but (let) replace the thermostat.

there is a motor with a flapper that opens and closes to keep your temp correct in the refrigerator side most likely the motor is bad and stuck open so your air from the freezer has constant flow to the refr side. the flapper is in the back of the refr behind a cover where the air flows in.

first run the diagnostics on the unit from the tech sheet inside the unit,then if thermistors are bad replace these there are 2 one on the left and one on the right wall in both fridge and freezer,if good per diagnostics then replace the electronic damper door located between the fridge and freezer compartments in the upper left hand corner of the fridge behind the plastic grille as these doors break and jamb open or shut and the temps can no longer be regulated during the diagnostics tests you can hear this door operate if its operating correctly,lastly,if these fail to solve your problem,replace the main control board in the back behind a panel

The thermostat needs to be replaced.

thermostat problem replace that if you know how to do that or call a technician who will help you

I had a similar problem where my evaporator coil was freezing into a block of ice, which caused my fridge to warm up due to a lack of air flow. I fixed this by doing a few things. I replaced the circuit board ($100) which was easy to do. Unfortunately, this didn't fix my problem so I took the inner fridge cover off to view the evaporator/heater coil assembly. I checked my thermo fuse and found it to be open (failed). I ordered the thermo fuse and the thermistor and replaced them both. I then plugged the fridge back up and put a regular thermometer inside the fridge to get an accurate reading of inside temp. A few days now and everything looks good. The board, fuse, and thermistor were all pretty easy to replace.

We had to reset the temperature, and what we did was hold the power freeze and the power cool button in for about 12 seconds. It flashed and reset it. My refrigerator still isn't working right but it seemed to reset the temp. I'm not positive this will work for you or not, but may be worth a try.

sound like the evap fan is not runnig which is a issue with the main processing board sometime it require changing the fan and the main board in the back of the rf

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Is everything really frozen or just the top shelf stuff? You may have a thermistor (temp sensor) problem if the compressor just runs and runs and runs all the time. Take a glass of water and place a thermometer in it for about 3 hours then take a temp. reading. That will let you know what the real temps are. See if you can cause the compressor to kick off and on by changing the temp settings (go to real low for about 5 minutes then back up to high). Let us know what happens.