795.74053410 Kenmore Elite Refrigerator (LG) Working too good?

[jasew503]

Model Number

795.74053410

Brand

Sears Kenmore

Age

1-5 years

Hello!

I have a LG Manufactured Kenmore Elite 795.74053410 French-Door Manufactured 10/2014 that had a recent compressor and dryer replacement, as well as a software/firmware update to accept the new compressor on 9/2019. Problem is, the unit freezes everything in both the fridge and freezer compartments, and has been doing this since the replacement. If I let it run, the fridge section will eventually get down far below freezing temp. This unit has dual evaporators, and I tore down the whole back of the interior of the fridge compartment tonight to see if there was something causing the temp sensor to not work, but everything looks normal and clean.

All the diagnostic stuff I've been able to find online are for LG units, and the Kenmore has a different control panel which is inside the top door jamb of the fridge.

I'm just now getting back to looking at this thing, as it's been sitting in my kitchen unplugged. Are there any suggestions anyone can give me on what to test to diagnose this problem?

Thanks!

Added complete model number

 

[rickgburton]

Recheck your model number. See if that 6 is maybe a 5? and the last three numbers are missing.

 

[jasew503]

Recheck your model number. See if that 6 is maybe a 5? and the last three numbers are missing.

Yes, I posted from my phone, it was a typo. Source is 795 (LG), model 74053, sub 410. So the string of numbers you're asking for would be 795.74053410.
I think I may have narrowed it down to a temp sensor in the fridge area that is giving erratic resistance values. Sometimes 22 ohm, then zero ohms, the 9 ohms, etc. So I ordered the part and will put it in to see if that fixes the issue.

 

[rickgburton]

22 ohm, then zero ohms, the 9 ohms, etc.

Sounds like a bad thermistor. Make sure you're on the correct ohms scale

 

[Jake]

Which thermistor sensor is it?

ACQ73244001 Temperature Sensor or Temperature sensing thermistor 6500JB2001B?

Jake

 

[jasew503]

Thanks for the replies. I think I was on 20k. The freezer-side sensor gave a consistent value. Fridge-side would show a resistance value for about one second, then nothing, I'd have to remove and replace the lead and it would show a different value for about a second, etc. The one I purchased on Amazon was 6500JB2001B, should come tomorrow.

 

[rickgburton]

Check it when you get it. When it comes to appliance parts we've seen lots of problems with eBay and Amazon.

 

[jasew503]

Check it when you get it. When it comes to appliance parts we've seen lots of problems with eBay and Amazon.

Will do! I'll reply back as soon as I get back in town after the weekend and I get it out of the mailbox and test it. Thanks again..

 

[rickgburton]

 

[jasew503]

Hey there! I took some readings on the new sensor, and it was giving a reading of around 12k ohms with an ambient temp around 68'F-ish. I installed the new sensor, and its continuing to freeze in the fridge compartment. I also took reading of the old sensor, and it was now reading the same as the new, with the reading higher around 17k-18k ohms when placed in a glass of water with 1 cube of ice in it and climbing as the water got colder (just to see if it would change). I have a feeling now I wasn't making a solid connection when testing the values on the original sensor, bummer. Anyways, fridge temp after a couple of hours was down to 0'F again when set to highest possible setting (46'F I think). Could this have anything to do with the 3-way valve in the sealed system not operating correctly?

Thanks again everyone!

 

[rickgburton]

... placed in a glass of water with 1 cube of ice....

I understand you were just checking to see if it changed but try this; Place the thermistor in a small glass with crushed ice (or cubes) and enough water to cover it. Wait longer than 3 minutes. This should bring the temperature of the thermistor to 32°F. At 32°F (0°C) the thermistor should have 30K Ω resistance ±5%

 

[jasew503]

I understand you were just checking to see if it changed but try this; Place the thermistor in a small glass with crushed ice (or cubes) and enough water to cover it. Wait longer than 3 minutes. This should bring the temperature of the thermistor to 32°F. At 32°F (0°C) the thermistor should have 30K Ω resistance ±5%
View attachment 48001

Thank you! It has a reading of 29.2k ohms in a glass of cold ice water with crushed ice after sitting for 5 mins. It has a reading of around 11k ohms in a room with an ambient temp of around 70'F.

The original sensor also gives pretty much the same readings. The original sensor has a pair of white wires, has a white tip with the marking "R4417" in very light yellow text on it. New sensor also has a white tip, but with no markings and has a brown pair of wires. I'm wondering if I should go through the trouble of putting the original one back in since it gives the same readings anyways and is an OEM unit.

 

[rickgburton]

That's the correct resistance. The only other thing I can think of is the main control board:

LG CSP30020907 Power Control Board (AP6892813) - AppliancePartsPros.com

This is a power control board that has been manufactured by LG for use with refrigerators. The power control board is critical as it activates the components of the refrigerator, such as the compressor and the fans, which are important for ensuring the appliance doesn't overheat. If the user...

click.linksynergy.com

 

[jasew503]

Funny thing about this, after the compressor was replaced it didn't cool at all, then they came back out to recharge it. It worked great for about a week, then started freezing everything.

Thanks again!

 

[rickgburton]

after the compressor was replaced it didn't cool at all, then they came back out to recharge it.

A sealed system repair throws a monkey wrench in the gears when a problem shows up at the same time. I don't know what exactly he did and if everything was done correctly.

 

[jasew503]

The only thing that worries me is if I order a new board, will it be compatible with the new compressor that was installed.... The guy with A&E Factory Service flashed/upgraded the firmware on the board with a jig to accept the new compressor, which he described as "a new universal compressor that LG claims is a permanent fix." He made it sound like this new "universal" compressor was an updated unit of some kind. After he flashed the firmware and brazed on the new compressor and dryer, he applied a vacuum and then charged the system. He said let it run for 48 hours, however it never cooled.

Another guy came a week or so later and noted that the Hi and Low side readings were wrong, and that it may have had a restriction due to a crimp during the first guy's install of the dryer unit. He evacuated the system, re-installed the dryer, vacuumed then charged and the pressures on Hi/Low seemed to read fine. Worked for a week (maybe only a couple days actually), then started freezing everything.

Probably a stupid question: Since this model has dual evaporators, is it possible that they are connected to the compressor backwards by accident?

 

[jasew503]

Tonight I went ahead and removed all 4 thermistors/sensors I could find, 2 freezer 2 fridge and tested them all in ice water. Readings were as follows:

Fridge Temp Thermistor: ~29.5k Ohms
Fridge Evap Thermistor: ~28.5k Ohms
Freezer Temp Thermistor: ~7.8k Ohms
Freezer Evap Thermistor: ~28.0k Ohms

Any other ideas, or am I looking at a board?

Thanks again!

 

[rickgburton]

The thermistors are good. There's no such thing as a "universal compressor".

He made it sound like this new "universal" compressor was an updated unit of some kind.

He said let it run for 48 hours, however it never cooled.

is it possible that they are connected to the compressor backwards by accident?

That's the monkey wrench I was talking about. It could even be the wrong compressor, too many BTU's. LG has been having all kind of problems with their new linear compressor. I have no idea what they are using to replace it but going by your description I don't think it's another linear compressor and the reason for the board update. Do you know what board was updated? I would think the driver board and not the control board but I'm not sure. Did he do the update correctly? Who knows? You're stuck between a rock and a hard place right now. If we were troubleshooting this problem with the original compressor and the thermistors checked good I would have no problem saying the control board is the problem. So the way I see it you have two choices. You can call the tech back and tell him the problem and see what he finds or you can replace the the board knowing it might not fix the problem but it might.

 

[jasew503]

Thanks for the reply. Unfortunately, calling the tech is not an option, as the closest tech is now 160 miles away. The tech that worked on LG no longer works for that company. So now I'm here trying to diagnose and repair this myself and reaching out to people on this forum.

There is only one board on this fridge that can take a software update, and it's the main board on the back of the fridge behind an access panel. He used the LG-supplied USB Jig to flash the firmware.

 

[Jake]

I'm not aware of this board being able to take a software update, you may want to ask at AppliancePartsPros here:

LG CSP30020907 Power Control Board (AP6892813) - AppliancePartsPros.com

This is a power control board that has been manufactured by LG for use with refrigerators. The power control board is critical as it activates the components of the refrigerator, such as the compressor and the fans, which are important for ensuring the appliance doesn't overheat. If the user...

click.linksynergy.com

Jake