Hi all,
I while back I ask this question:
I checked the thermistors and found the freezer thermistor with a reading of 27k @ 0F. So I thought it was a bit out of range so I changed it. After that I noticed that the fridge didn’t run as much as it used to. So I thought the problem was gone. It’s been 3 weeks and the frost in the rear of the freezer is back and the temperature is higher until the next day. Not all the frost is gone the next day but after a couple of days it is gone. I recheck the thermistors (with frost in the rear of the freezer) and this is what I found:
Freezer Thermistor: 39.5k @ -1F
Evaporator Thermistor: 60k @ -1F
FF1 thermistor: 14.6k @ 37F
FF2 thermistor: 16k @ 37F
I’m thinking the evaporator thermistor resistance is high but there was ice on the rear of the freezer (and probably on the evaporator) which tells me it is ok.
I check the continuity for the heater and over temperature thermostat between the blue and orange wires and it showed 23 ohms. The schematic for the fridge which I found under the grill shows it should be 22 ohms. BTW I tried to attach a pdf of the schematic to this post but I couldn’t figure how.
I also checked if the doors switches (freezer and FF) provide power to the main board. They showed 110ac when the door was open.
I also checked the evaporator motor between J2-3 and J2-8 I have 13v. And between J2-3 and J2-4 about 10v. I read here about a square wave reading with a scope but I didn’t check that. I could thought, I have a scope.
The original reply says to check the "defrost limiter" but I don’t know where that is or if it is the over temperature thermistor.
I’m about to replaced the main board but I’m no expert at this.
What do you guys think?
Thanks