Freezer doesn't always come out of defrost mode

About a year ago I described the following problem and was advised to remove the back cover, clean dust from the back of the unit and check the heater in the freezer for continuity. I did both things and was then advised to replace the defrost thermostat. I did and it didnt solve the problem. The unit sometimes runs fine for several weeks, showing temps of 0 degrees in the freezer and 37 in the food section, but sometimes it seems to go into the defrost mode and doesnt come out until the temp in the freezer is well above freezing to the point where the ice cubes are melting. When this happens the freezer temp displayed on the door indicates anywhere from 5 to 10 degrees (even though everything is melting) and around 40 to 45 degrees in the food section. I have to keep a plastic tray under the ice maker to catch the water when this happens. One other clue is the water dispenser in the door doesnt work, seeming to indicate something is frozen. I have to remove everything from the freezer and use a hair dryer to warm the evaporator cover for anywhere from 5 to 20 minutes. Just when it seems like its never coming back on, the freezer starts up, the water in the door works fine again and I can put everything back. It may act up again in a couple days or run fine for many weeks. Today I also cleaned the back and re-checked the heater for continuity, they were both fine. What is going on and what do I need to replace to fix this? (One other thing, I have to replace the water tank in the food section, it must have frozen and cracked, it’s’ leaking whenever you get water out of the door)

You have a bad mother board. This is the timer for defrost mode. If it is sticking in defrost mode, and then suddenly starts working, the relay on the board is sticking. You will need this part to fix your problem. [part]AP4436216[/part]

Sealed system & mother board replacement parts for General Electric GSS25KSTBSS Refrigerator | AppliancePartsPros.com

They did a better job of wave soldering the new boards, so you probably will have no more problems with this board, but I would put a 1000 joule surge protector on the wall outlet as a power surge probably blew out the motherboard.

Thank you both for your advice. My concern is then why does the temp displayed for the freezer never go above 20 degrees, but the inside temp of the freezer is obviously well above freezing. (the temp displayed for the food side always seems to be accurate) I would imagine if the freezer had completed the defrost cycle all the ice would be gone and if a stuck relay was the problem, then the evaporator wouldnt still be iced up. After I melt the ice by hand, how does that unstick the relay and let the unit come back on. Does the part that determines the temp inside the freezer have anything to do with the unit coming back on? (It seems that as I heat up the inside with the hair dryer, the temp displayed slowly rises and once it gets close to 20 degrees, it kicks back on) Im trying to avoid the expense of replacing the mother board and finding out it was some other part. If I left it alone, it would come back on on its own, just everything would melt and then refreeze. Thanks again for your help on this…

You can remove the motherboard and check the back by the big power relay, may have bad solder joints you can re-solder. If you have a meter, you can check your thermistors to fix the temperature problem.

Them I’m guessing the defrost cycle has nothing to do with temperature and is a simply a timed event controlled by the PCB.

The evaporator thermistor and the defrost thermostat work in some way to terminate defrost, nobody except factory service guys know. I would check your thermistors with a meter, or just replace them, one is clipped to the top of the evaporator, a long,white, plastic item. The others are in the damper assembly in the fridg section.

I spoke with GE today. They said there was no recall on the pcb but they’re sending me a replacement anyway. My serial number was one of the first ones made. If its still acting up after I put it in, I’ll check/replace the thermistors as you suggest.
Thanks again…

The new board has only been in a couple days and so far everything seems to be running fine. I never did find out how often the defrost cycle happens, so it’s a waiting game. The problem was intermittent and sometimes the unit seemed to run fine for weeks. I’ll keep a eye on it and if the old problem comes back I’ll post something here the same day. I did check the back of the mother board and found no cold solder joints on the relays or anywhere else. I was a printed circuit board test and component level repair tech for many years. The rest of the board has no obvious problems either. I’m hoping its fixed now, all that’s left seems to be the freezer thermistor. How often do these units perform a defrost cycle?

This unit goes into defrost about every 10 hours. Hope this helps.

I think Gene might help here, but there is no way this refrigerator initiates defrost and terminates defrost in a set period of time. These both are determined by many factors in some complex way that only very expensive equipment can determine.Any statements by GE are probably just guesses.