Lg Test Mode Refrigerator

0 views

Skip to first unread message

Tom Donahou

unread,

Aug 4, 2024, 9:57:26 PM8/4/24

to trensemtymoun

Freezeris working, but was too cold at -16 degrees. Fresh food compartment not cooling, was about 65 degrees. I did some disassembling and found coils just on top of freezer but behind lower part of fresh food compartment are covered with ice. Also found a fan there. I suspect that fan is not working. Blades spin freely, but when I close doors on fridge I don't hear it kick on. There is another smaller fan that sits right nearcthe water reservoir . I think its to cool the water. I did not see thatone turn on either. I do see the fan in freezer turning. It turns even when I have freezer door pulled open. I'm curious if that is normal operating since for fresh food compartment, fan is supposed to turn off when you open doors. So I'm not sure if freezer fan is supposed to run when freezer is open .

So I want to put it in diagnostic mode to see if maybe other issues like defroster, bi metal, etc.. is messed up. The plug on the fresh food fan is those 6 prong ones. Not sure how to test? Please any help greatly appreciate.

Replacing the refridgerator evaporator fan has fixed the problem. Couple things to mention in this experience: testing the fan with a multimeter for ohms or voltage as suggested by many just dis not work for me. I did as instructed with multimeter and got dame results with old fan and new fan. Kind of lead me to think that it was not the problem since new fan was giving me same results. But I slapped the new fan in and came right on . So unless i was testing fan the wrong way, seems test results are unreliable. Change the fan any way. Thanks

An Electronic diagnostic test mode shows all thermistors passing, but the J1-1 FF evaporator thermistor resistance is much higher than the rest of the thermistors when tested on the J1 motherboard location. I am guessing it should be replaced, howerver...

That same J1-1 FF evaporator thermistor has a unique cord design which inserts into a round hole in a cold sink block on the back of the FF evaporator. I do not see that thermistor part on the parts assembly diagram so is it a unique part?

I did all of the fan tests, as well as other tests shown on other videos on your site and everything else seems to be working. The motherboard visually looks fine with no obvious problems (burning, capacitors, resistors, fuse, bad solder joints).

I have replaced the bad thermistor, main control board, and inverter control board. The compressor resistance values are equal across the 3 windings. The compressor is now running and warm but I have zero cooling.

Could it be a freon issue? There is not a refrigerant valve in the original system so would have to add one to check system pressures. I did have frost on the evaporator coils last week when I noticed things in the freezer were not frozen, but now I cannot get any amount of cold in the coils.

Yes it could be a sealed system issue. Rest of the easy checks are condenser clean, condenser and evaporator fan running. Any heat on discharge line going to the condenser? Presume you let it run for at least a couple of hours with doors closed to check for full frost pattern. If that was all good then it would be time to tap the system.

I am retired military living on a fixed income requiring me to repair everything I can myself. I have a 3 year old LG French Door fridge - LMXS30776S/03 - that initially, had water damage on the front display unit within the water/ice/display insert. At the same time, it stopped cooling and freezing within both compartments. I purchased a replacement display/water/ice unit and installed it into the left door cavity the old waterlogged one once was located. I thought this was the reason the fridge stopped working since I was unable to effectively use all the controls once water seeped into the unit. Unfortunately, after spending $250 on the replacement display unit, the problem did not rectify itself: it still does not get cold or freeze. After looking at several YouTube videos on how to test for the problem, I removed the upper and lower rear plate per the instructions.

BTW, the display unit on the old waterlogged unit no longer worked properly but worked perfectly when I installed the new replacement unit. But unfortunately, it did not solve my problem of the cold air and freezer compartments working properly.

When I plugged in the fridge, I found that the fan was turning properly and the black compressor on the lower left side was vibrating. The YouTube video indicated that meant my fan and compressor were likely good and were not the problem. I then moved on to the next phase of the video's suggestions and pushed the test button to initiate a diagnostic test.

The test cycle was interesting: what I found was there was no air at all going into the upper and lower sections of the fridge (upper two compartments to keep food cold: lower freezer to freeze items). However, when the test cycled through the test sequences, there was suddenly cold and freezing air blowing into the upper and lower sections of the freezer. When the test ended the air stopped flowing into both compartments as the unit went back into its normal cycle when I unplugged the fridge momentarily and plugged it back in. (the compressor and fan were working but no air was moving into the fridge).

I opened the door and looked at the "Multi Air Flow" square at the rear top of the cold air compartment. It had a marking saying "open" on the top left and a "close" on the top right. I tried pushing both sides to see if that affected any air flow but it did not: no matter how much I "fiddled" with this 4" square, nothing affected the air flow at all. Still no air flowing into the compartment above or below.

1)when I installed the new display/water/ice unit and plugged that unit into the various plugs (after cleaning out the interior of dust etc), I found there was one open female plug with no male plug off the new display unit to plug into. Is this ok/common? It is located on the top right corner of the new replacement unit. I was worried that this might have to be plugged into something, thus causing my problem, but I am unable to find any wires on the fridge male plugs or the new replacement unit male plugs to go to that female receiver.

2)what should be my next step? Should I replace the entire circuit board? Would that seem to be the problem? Perhaps the faulty circuit board on the back of the fridge has a problem sending a signal to open a "butterfly valve" that would allow air to flow into the cold air and freezer air ducts?

3)does my logic above make sense and am I heading into the right direction as far as troubleshooting the problem step by step to the point where eventually, I will solve the problem by replacing the correct part that has failed?

I checked the LG fridge again and ran the tests through the button on the rear circuit board. There is air coming out of the top back of the top compartment as well as out of the two vents in the door during the test. However, when the test ends, there is no air at all coming into the fridge even though the fan is turning and the compressor (that is what the large black "tank" is called at the bottom of the rear fridge, correct?) seems to be running (there is a vibration on it when I place my hand against it).

What do I do next? Any idea why the test sequence makes air flow into the freezer and top section but when the test ends, there is no air going into the two sections at all and the fridge is +- 60 degrees.

I am at a lost what to do next. We have six in my family and we have been without a fridge for 20 days now, using an ice chest to cool our food. I can't afford to guess what to replace next or buy a new fridge.

The test mode runs the all the fan and compressor at 100% duty. This mode ignores the door switches and let the fans run with the doors open or closed. We established that the fans will work and the compressor is doing it's job.

@Quick If the info Skip70 gave in the first post is correct then it would seem this isn't the famous failing linear compressor problem in this one, (could very well be the reason you haven't seen anyone suggest that it is a compressor or sealed system problem).

*there was water damage to the display panel next to the ice/water dispenser, so I purchased a new one because I could not set the temperatures and thinking that was why the fridge wound't cool/freeze. However, the new part did not solve the issue of no cool or frigid air going into any compartments.

*it has been suggested i test the door switches. How do I do that? I ran a magnet along the edge of the top and side of the doors but nothing happened. Was the magnet supposed to indicate an issue with the doors? But if that was an issue, wouldn't it be centralized to one bad door versus every single compartment in the fridge getting no cold or freezing air?

*what should be my next step? Is it possible the pcb board is bad? Is there a way of testing the compressor? Wouldn't a bad compressor make some sounds or have some inconsistent vibration indicating an issue inside?

Measuring dc voltage at the board. Check all door switch circuits. Custom chill switch is con7 pins 29 and 30 (white wires), Freezer switch is con7 pins 31 and 32 (yellow with black tracer), refrigerator door switch circuit has 3 switches in series and is con5 pins 13 and 14 ( 13 is red with yellow trace, 14 is a gray wire). Check for 0 volts dc when doors are closed on each circuit. Check for 5 volts dc with the door open on each circuit. In normal operation the board will turn off the evaporator fan when the door is opened. Beleive the custom chill and refrigerator sections share the same fan. Freezer has it's own fan.

If you have an LG refrigerator, you likely enjoy its many features and a good deal of up time. The appliance manufacturer is known for high-quality units. However, things go wrong with every appliance after some time. If you need to diagnose a problem with your refrigerator, you can do so simply by putting it into test mode.