Hello!

I need to give some background to the situation so that maybe we can help each other find a solution, so bear with me!

I recently acquired a Kenmore 795.72053.110 french door refrigerator. The person who owned it before had a tech diagnose that the compressor was bad. I ordered a new compressor. The new compressor part number is TCA38091801. This new compressor number superceded a number of previous LG compressor models. This new compressor also requires a software update to the control board or else it will fail prematurely, according to LG. In order to update the control board, LG sells an "update jig" part number CJT30000002. It is a usb stick that you plug into the PCB and it is supposed to update the board automatically. This is where things get fishy!

When trying to update my PCB, there were two ports it could fit: CON202 and CON9. I did figure out that it is CON202 that I need to plug into for the software update. The jig comes with 2 connectors: a white connector if pin 1 on CON202 is the TX pin or a red connector if pin 1 is the VCC pin. The instructions for the jig do say that you can check for resistance between pin 1 and 2 and pin 2 and 3. This is where the instructions stop being clear. Pins 1 and 2 have 19k ohms and pins 2 and 3 have 10k ohms. (I will check again today to verify that those numbers are still correct.) With that information I still cannot explicitly decide if I am supposed to use the white connector or red connector. Unfortunately for me, neither connector is allowing the jig to update the board. The jig says "failure unplug pwr cor". I spoke to someone and they said that LG had a manufacturing problem with the jig's white wire and that I should check for continuity on the white wire circuit. It checks out good. That person said that if it is still not updating, then the board must be bad. So I purchased a new PCB!

The new PCB number is EBR75234703. My question is, does the new board EBR75234703 still need updated to run the new compressor TCA38091801? If it does, how do I determine which connector (white or red) to use to update the board?

Sorry for the long read but the only thing stopping me from fixing this fridge is updating my board. I dont want to ruin the new compressor. LG and Sears customer service and support are totally nonexistent. For as common as this issue is, I cannot believe how little information there is out there. I hope this changes that. Thank you.

Collin

OK, I found help on an eBay auction for the compressor and jig:

There are two harnesses off of the jig one will say TX and the other will say VCC.

The main pcb connector to use on connection CON202.

If TX or VCC is not written on the CN202 connection you will need to check the resistance between pins 1 and 2 and pins 2 and 3.

If the resistance is higher among pins 1 and 2 then use TX harness connector. If the resistance is higher among pins 2 and 3 then use the VCC harness connector.

This entire process takes about 2 minutes and can be done while creating the vacuum.


I tried this and measured 14K between 1 & 2 =, and 10K between 2&3, so I used the Tx (white) cable.
The firmware did update. now to do the compressor swap.

Rocndav, thanks for this.

I was about to blow a gasket when I received my replacement compressor and it was a different model and required a software update. It might have been nice if the vendor mentioned that I wouldn't be receiving the model that they actually show for purchase. Had I known, I could have gotten the jig a week ago. Now, I'm held up again to finish the repair.

It looks like I have the same model fridge, but the mainboard number is different. I will post back when I do the software update.

What will happen if you run the new compressor without update?

Edited by user Thursday, April 29, 2021 11:23:28 AM(UTC)  | Reason: Not specified