16 replies to this topic

[Samurai Appliance Repair Man]

Went on a call for an LG LFC25776ST/00 refrigerator today. Complaint was that the freezer was warm but the upper compartment seemed okay. Found the evap fan not running. My troubleshooting points to a bad muthaboard (main PCB in LG terminology), p/n EBR67348002. Here's the video of what I did. Looking for a second opinion/confirmation/critical review of my work.



Is it still possible that the evap fan is the problem? Should I order it in addition to the board?

Also, this board is backorder from every vendor I use, including APP and Marcone (RC doesn't even carry it). Anyone have a source for this board?

Domo!

[kdog]

I believe that one of the functions of the "defrost control" is to allow the evaporator to flood prior to initiating fan and would therefore be looking for a fairly specific change in resistance once compressor is started - possibly the thermistor in the control has suffered some "freeze-thaw" damage ?

http://www.repaircli...mber=LFC25776ST

[Samurai Appliance Repair Man]

Hmm, interesting angle, kdog. If this thermistor was damaged, would the unit even initiate a defrost cycle? Also, there were no error codes in the display-- not that error codes are conclusive-- but there are specific error codes for the FF, FZ, and DF sensors. If the DF thermistor was damaged, would this trigger an error code?

[kdog]

Probably depends how it has failed - from what I gather, the sensor readings are also used to determine frequency and lengths of defrost cycle depending on loads/demands etc.

[Samurai Appliance Repair Man]

It's worth going back and checking the defrost sensor. That function of the defrost sensor looking for the evaporator to flood is sublime-- wish LG was clearer about little tricks like this in their documentation.

So you're not convinced the board is bad?

[kdog]

Hard to say, but if there are that many backordered etc that may tell a story - not sure if you would be able to catch that act with a meter (temp change rate etc) - just thought I would throw some fuel on the fire

[Samurai Appliance Repair Man]

And good fuel it is! So much so that I'm going to pose that question to LG over the LG Tech site. I'll post back what they say, they're generally pretty quick about responding, should hear something back tomorrow.

[kdog]

You gonna need one of those controls in your stock sooner or later anyhow, might as well buy one and have a "known good" substitute

[RegUS_PatOff]

You gonna need one of those controls in your stock sooner or later anyhow, might as well buy one and have a "known good" substitute

seems that may be the only LG model number that uses that board.

[Samurai Appliance Repair Man]

True enough and good advice. Adding it to my parts order now.

Just posted a ticket on the LG tech site. I'll post their reply here.

[kdog]

seems that may be the only LG model number that uses that board.

Was referring to the Defrost Control

[Rodgers Appl.]

Just checked ebay and i found some boards there if you cant find them anywhere else. I have found that I have to go there alot for some parts. It seems to work good but have to wait a little longer for shipping.

[Samurai Appliance Repair Man]

Domo, RA! I'll check it out.

[Samurai Appliance Repair Man]

Got the reply back from LG tech support. They confirmed that I just need to replace the main PCB (muthaboard). And now the Great Part Hunt begins!

[kdog]

Did you get this one sorted out then ?

[Samurai Appliance Repair Man]

It's still a work in progress. Replaced the Muthaboard and no change. Called LG techline and they said the problem has to be a software problem on the board and that I must have gotten a bad new board. They want me to replace the muthaboard yet again. So I've ordered another one (on back order). LG says if that doesn't fix it, they're going to replace the refrigerator for the customer. Cool dat!

[kdog]

Argh, then nobody learns