LG Washer WM2250CW Problem

[kgvickers]

My LG washer has died.  It appears to turn on but then turns off after a few seconds.  Unplugging and doing the 5 second power button/run button depress isn't working.

We bought this used from an individual about four years ago, and he'd owned it for three years.  I found what I assume to be a date code on the circuit board of 2012.

I've pulled the top and checked all the connections I could easily reach.  I've also pulled the control board and inspected it closely for any obvious problems.  I was hoping to find a bad cap but no luck.  Of course, that would be a tough repair - I've never seen so much conformal coating on any other circuit board!

I don't know if this is germane to the topic but a few weeks ago after running a load when I opened the door to remove the clothes I'm pretty sure smoke was coming out ... or it may have been steam.  Unfortunately I've lost most of my sense of smell so I don't know if it was steam or smoke.  If it was the smell of burning electronics I wouldn't be able to detect it.  Shortly after that I ran another load and it appeared to work fine until a few days ago.

Thanks in advance for any and all help.

Info from the tag:

Serial: 202KWZH1A021

MODEL: WM2250CW

Product Code: F12A1FD.ABWEEUS

 

 

[john63]

Open the door.

Grab the stainless steel inner drum and pull/push on it.

Is it loose?

 

[kgvickers]

No, seems fine. I’m not feeling any bearing play. Spins easily by hand. 

[john63]

Most likely a failed Main Board.

The diagnostics method to verify would be to check for 120 volts at the pink connection on the Noise Filter (with plug pulled off).

If 120 volts detected/confirmed...failed Main Board.

If no voltage...possible failed Noise Filter or...power problem at receptacle/fusebox.

 

 

[kgvickers]

I think the filter is good. It’s within 0.2 V of the input voltage.

[kgvickers]

Any idea which component typically goes bad on that board?

[john63]

Usually the large power relay (1 of 2).

[kgvickers]

Hmmm .... dirty contacts no flowing enough current?

[kgvickers]

I can easily trim the lid off with a Dremel cutter and clean the contacts.  Which relay is it?  Looks like there are three on there, a black case and two blue cases.

That would seem to partially explain what I'm experiencing ... if I hold the power button in it sorta works. Looks like there are three on there

[john63]

3 minutes ago, kgvickers said:

I can easily trim the lid off with a Dremel cutter and clean the contacts.  Which relay is it?  

I don't know...

Best guess...the black relay.

[kgvickers]

Hmm, power is going in on spade 4 which per my meter is the normally open contact.  The washer comes on momentarily so I think the relay is working properly and engaging the normally closed contacts.

Not getting any codes - Is there any check that it does, fails, then shuts down?

I'm not familiar with that relay construction.  No doubt I'd trash it trying to get it open.

[john63]

16 minutes ago, kgvickers said:

Not getting any codes - Is there any check that it does, fails, then shuts down?

Main Board failure...typically will not trigger an error. I've seen a "CE" (communications error) maybe once. I believe that one case was due to wiring.

As for dissecting circuit boards...that is not something we delve into. 

Main Boards are replaced for the customer...then we move on.

[kgvickers]

Bazinga!  If I scooch the yellow connector, with the blue wire that goes to the "cold" leg from the wall, over to contact 4 then the washer comes on and appears to work (only played with it for a few minutes) as soon as I plug the cord in.  That stupid relay is a $3 part.  I'll cut the plastic out from the bottom of the circuit board assembly, peel away the conformal coat, and replace just that relay.

Nothing to lose at this point.

Assuming I don't kill myself, I'll let you know how it goes.

(not too worried, I've done much more stupid things)

[john63]

Good luck:)

[kgvickers]

That relay is a simple SPST, nothing to it.  Likely the contacts are just worn out.  The standard one I see on the net has a lid that looks like it would be easy to pop off, which would allow me to clean the contacts as a temporary fix.  The one on the circuit board is different, no removable lid.  So I'll be doing the deep dive to replace it.

The relay is a Tyco Electronics PCF-112D1M-2D.  It's worth noting that BMW uses Tyco relays in the power door lock control module of the e46 (1999 - 2005 3 series) and they are notorious for having contacts go bad.  I fought those until I got tired of working on my BMW all the time and got a Chevy Volt, a wonderful vehicle, BTW.  Hmmm, but that Volt has batteries made by LG .....

With my cheapo handyman rigging the washer comes on as soon as I plug it in and a red LED on the board illuminates (this is apparently normal because it would temporarily illuminate before my modification).  The controls appear to turn off when I depress/release the power button (normal operation) but that red LED remains illuminated (which I assume is not the normal condition).

I'm testing with the "Tub Clean" setting (no clothing) and so far it appears to be working fine.  I'm going to closely monitor until it finishes and see if the front panel controls/lights turn off.  However, until I replace that relay I'll be unplugging when not in closely monitored use.

John, thanks soooo much for your assistance.  No way I would have figured this out without that nugget about the relay!

Cheers,

Keith

[chris_goulet]

Were you successful in repairing that board?

For the record, I repaired an EBR78263905 board in a WM2650HVA (2012 production year) that would not power up unless they unplugged, then pressed "Power" for 5 seconds, then "Start" for 5 seconds, then plugged back in. (Don't understand how it would do anything while unplugged!)

The board is heavily potted, so I used a Dremel cutter, and made a rectangular hole in the white plastic under the X71 yellow relay, peeled the potting, and pulled the relay. Unfortunately, two through holes got pulled out, so I added wire jumpers (one insulated, and the other bare copper) through an existing hole beside X71, to R72 and the ceramic fuse. I replaced the "XMHF" brand relay that has two quick connect terminals, to a Panasonic ALF1T12 (12VDC, 20A @ 277VAC, SPST) relay, from Mouser Electronics.

My client has done 6 loads without issue, so looks like it will last.

 

Edited February 2, 2021 by chris_goulet

[chris_goulet]

Con'd from above:

Normal behavior: When plugged in, the LED on the board should NOT light. When press "power", that LED should then light up. When press "power" again, the LED should stay on for about 90 seconds. There should be a relay click about 10 seconds before the LED goes out, and another click at the same time as the LED goes out. If this behavior is different for this model, or similar vintage, the X71 relay is likely stuck closed when 12VDC is de-energized, or fails to close when 12VDC is energized.