Hi,Welcome to Just Answer, My name isXXXXX will be helping you with your appliance issue today.
When you had the freezer apart how much of the evaporator coil was Frost up an frozen? Was it all the way up all the coils really thick Frost? Or was it only two or three coils or half the coils? Is it frozen up again now? Did you completely defrost this with a hairdryer and get all the Frost off before restarting the refrigerator?
I replaced the control board behind the thermostat
yes, thats the one
Okay, I believe you were given bad advice unfortunately, it's most likely either the defrost thermistor,this is what tells the refrigerator to go into the defrost cycle and also tells the when to shut the defrost cycle off, I do not believe this is sensing correctly, the other part that could be bad would be the defrost heater itself, more commonly though it's the thermistor, like I said this tells the heater to come on off when these defrost, what this is not doing is defrosting that's why all that frost is on the coils, I would replace that, it is clipped onto the top of the evaporator coils, the coils you are defrosting right now, it's number 14 on this diagram, you can order this at the following blue link
http://www.searspartsdirect.com/partsdirect/part-number/Kitchenaid-Parts/Refrigerator-Parts/2188820/0046/106/Model-KSSC42QMS01/059 3/0165000?keySuffixId=NA&productTypeId=x&searchModelNumber=KSSC42QMS01&subCompDesc=Lower%20unit%20and%20tube%20parts&brandDesc=KITCHENAID&modelDesc=BUILT-IN-REFRIGERATOR&blt=11 I believe this will take care of your issue, hope this helps, thanks, Bryan
The thermistor tests (1 & 2 on the diagnostic) passed but the control goes black on the 3rd step....
there are only 2 steps - passed both. Fails on the 3rd - Evaporator Fan Motor which was first thing replaced.
Step 1 is FC Thermistor, "01" pass
Step 2 is RC Termistor, "01" pass
Display goes black on 3rd step - Evaporator Fan Motor, replaced
Sorry to be so long Dave, I had to go out and bring my mother dinner, she is 86 and I take care of her, okay if you already replaced the evaporator fan motor you are correct the board has been relay on it., You say you already picked up the board? Is this the control board you picked up?
if that is the board this is part # XXXXX on this diagram, you need to pull the refrigerator away from the wall and its in the back near the compressor, in a box. take screw # XXXXX out and its in there, hope this helps, thanks Bryan
P S heres a link to all the diagrams for your refrigerator.