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ZISS420DRISS GE Monogram Freezer too cold and fridge too warm

Jimmy W

Premium Member
Aug 31, 2019
orange county ca
Model Number
More than 10 years
I have a GE built in and that has the freezer set to 0 deg and FF side set to 35. The freezer is now -12 deg with the FF side at 50 deg. I read as many post on this board as possible and thought it may be the damper, so I took apart the foam around it so I can see it. I ran a diagnostic 1,6 and the damper opens and closes. I also read that perhaps I had a bad evaporator fan. I don't understand the air flow enough to know when the evaporator fan should turn on. I am assuming that is should turn on to blow cold air into the FF side with the damper open. I can see the fan from the FF side and it is not running. The only time the fan will run is when I have kept the freezer door open for more than a few minutes.

Any help would be totally appreciated.
I read more posts from that thread and decided to leave both doors completely open to defrost the evaporator. I put my finger up to check it last night and it did seem to have ice but not a block of ice. Regardless, I woke up this morning and it was completely defrosted. I turned the fridge back on. Let's see if that was the issue. Additionally, I wasn't aware how the fan worked. I now realize that the fan is working properly. Previously, I was trying to check if the fan was working by looking in the freezer from the FF side of the damper. But what I didn't realize was the fan turns off every time I open the door. So I think the fan is operating correctly.
WR55X10560 Board Asm Main Contro

Check the fan voltage and thermistor values at the main board. J2-3 to J2-4 is the evaporator fan motor voltage (about 12 VDC). J2-3 to J2-8 is fan motor supply voltage (about 13 VDC).
GEMB-13 WR49X10152.jpg
The Fridge and Freezer are both working now, after the overnight defrost. I suspect that the evaporator was frosted over since the tray under the compressor was full of water. As a precaution I decided to replace both the inverter and control board. Do yo think that is overkill? I did my best with the Multimeter but couldn't figure it how to get a reading on the ohms setting. I am still worried that maybe on of the thermistor is bad and the problem might show up again.
Ok I am such a dummy. More testing, I figured I needed the fridge off and got the following readings. 1- 8.3ohms, 2-7.4ohms, 3-10.92ohms , 4-10.55ohms. The freezer is currently at 8°F and fridge at 36°F. Does this make sense? And this is on the new board.
Jimmy W said:
I decided to replace both the inverter and control board. Do yo think that is overkill?
oh yeah
Jimmy W said:
Does this make sense? And this is on the new board.
no, you should be measuring the thermistors in the connector. thermistors are variable resistors that change value with temperature

R-GE Thermistor Chart.jpeg
Excuse my ignorance, but when you say connector, you mean the connector on the board like your picture? I did use a multimeter and test on J1. I will let the fridge settle out tonight and check again.
I must be doing something wrong. I tried pushing the probes through where the wires are with the connector plugged and get the same readings. I also tried with the connector pulled off and get about the a reading of 18-19ohms on all four. This is while all the unit is unplugged.

This is how I do it.

safety pin 500x250.jpg

To check a thermistors accuracy, place it in a small glass of crushed ice and enough water to cover it. At 32° F the thermistor should have 16.3KΩ

R-Thermistor Testing.jpg
You are awesome. Thanks for the tips. Just to double check. I should be testing with the fridge off and connector plugged in?
Jimmy W said:
I should be testing with the fridge off and connector plugged in?
Machine unplugged and connector disconnected from the board. Insert test lead into J1-5 (common) and leave it there. Measure each thermistor with the other test lead.
Success! All the thermistors are reading as expected. I think you were correct on another post that perhaps the condenser was iced up. Since I defrosted it I think there is good air flow. Since I have never completely defrosted, do you think this was a one time occurrence? Or is there another part that I should replace?
Jimmy W said:
...perhaps the condenser was iced up
Evaporator. If you didn't fix the defrost issue the evaporator will frost up again. Replacing the main board may have fixed it. It usually takes a week or longer to build up enough frost to affect the cooling.
Thanks again. Rick. I am learning a lot through this process and it was so helpful with you assistance. I will post again with an update in a couple of weeks.
Back again after one year. The fridge is warm again. It has only been one year and was going to replace the Control Board again but thought I get some advise before moving forward. Should the control board go bad only after one year? I checked the evaporator and it didn't feel frosted over. I ended up emptying the unit overnight and turned it back on. It working now, but do you think it might frost over in 1-2 weeks if I don't change the control board?
Where did you buy the control board at?

If you bought it from Rick's link in post #3 to it at AppliancePartsPros you have a 365 warranty on it.

Yup Jimmy, that's why I always advise folks not to buy appliance parts on amazon, it may be less expensive, but it fails usually at about 1 yr or less.

Ohm test your evaporator thermistor and defrost heater to make sure its the control board again.

Don't know the reason why but we've see a lot of problems with appliance parts from eBay and Amazon

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