Need Appliance Repair Help? Ask a Technician for Answers ASAP
Thank you for using Just Answer. I will be glad to assist you in your answer.
Please open the freezer door and tell me if you hear the fan running?
Actually, it is turned off and doors are opened since last evening to make sure it is completely defrosted. Should I plug it in and see what is going to happen? I suspect the freezer will come on as it did earlier.
It will be hard to diagnose with all defrosted., But a few thing needs to be known, if possible. Does the freezer fan run?. Was there frost on the back panel of the freezer before you defrosted it? Did the freezer seem to work ok before you turned it off?
Yes, the freezer fan was apparently working fine, and with the controls set at the number 5 setting, the freezer maintained about 0 deg. to 5 deg., and yes, there was a little frost on the upper walls around the ice maker area. After the last defrost attempt, both sides appeared to work fine, until at about 36 hours later the refridge area started to warm up, and over the next day got up to and over 50 deg.
From your description, you have a defrost problem. Each of these parts have to be good for the defrost system to work. Having an engineering background, I assume you know how to use a voltmeter. You will have to use the continuity setting and ohm setting to test. Behind the freezer panel is the evaporator coil. On the bottom side of the coil is the defrost heater. This heater need checked for continuity, frig unplugged. If that is good, then the defrost thermostat will have to be checked next. The coil will have to be cold for this test. This little roundmetal device has 2 wires to check continunity by. If that is good, then next will be the themister, also at top of coil. You will actually test this at the control board located behind the 8x12 panel on the back of the frig. Place the thermistor in a glass of ice water for 5 minutes. At the j2 connector on the main board wire 4 and 5, counting from the left, you should get 16.3k ohms(+ or - 10%).
If all those parts check good, then the board will be faulty. You can test the heater and the thermistor now. But the defrost thermostat will have be cold from the coil running for while before you can test it. There is a great youtube video on test the thermistors, how to test ge thermistors....check it out. I know this is a lot of info, but if any one of these device is bad, defrost will not work, and coil will frost up. When this happens, the airflow gets cut off to frig, warming it up slowly, and actually warming freezer to, but will still be below freezing. If you get stuck on test, or not sure what I mean just respond back at anytime, and I will get back to you asap. I do this on the side, so please abre with me in time. If at anytime you feel that I hae answered your question please hit the green ACCEPT button. This is how we get paid for our time of the questions. Thank you.
I can check the defrost heater for continuity - frig unplugged.
I will plug in and wait, then check the defrost thermostat next. Should I be "unplugged" to check this.... only after allowing the system to run and cool down first? And lastly, Am I to remove the thermistor at the top of the coil? I am guessing the thermistor is the equivilent of a of a thermocouple?? And finally, how do I re-open this chat, as I am pretty sure this testing will take a while
Yes, it will take a little while since the unit is hot, You should be able to unplug the wire harnes to check the thermostat without unplugging the frig. The thermostat and the heater should be able to be checked with this harness. You canould wait until the coil is frosted thru before checking both of these. And at that time, then you could check the thermistor in the ice water. And please chekc out that youtube video to check that. It is a great video demonstrating what to do. And if you find that the board is faulty. Just respond back to this question, and I can verify that with you by another test. But, you need to leave the unit running before responding back to do this test. So, all-in-all, plug the frig back in, and do these test when you get home tommorow, and let me know what you find out. Then we can go from there.
Ok, I did check the defrost coil, and found that it does have good continuity. I then checked the thermister by checking its continuity at the board contact points. But I didn't remove and put the thermister in ice water as you said. I didn't see how to remove it from the coil to do that. Can you explain that thermister removal and check again please? I looked on U-tube for that video, but (I'm not much of a user of U-tube) couldn't find it. I did a search, but didn't find it. Is its continuity checked as I did it of any value? Or is it neccessary that I check it as you described it critical to understanding the problems?
Yes, thermistor has to be checked the way I described to know if good, or not, still can do the check from the board. If the unit has been running for 24 hrs, you can unplug the frig, and go to the main board. Unplug the blue 3-wire connector at the bottom of the board. Jumper the wires that correspond line and htr (jumper the plug, disconneted from the board). Make sure not touching any metal, then plug unit back in. This should make the defrost heater kick on. If it doesn't come on, that the defrost thermostat is bad. If it comes on, then you will have to test the themistor to be good. Then have proof to order a control board. Let me know what part you find you find faulty, and I can give you part#'s. Thanks