LG Washer/Dryer Power Fail

[hugokernel]

In this case, I was confused by the thread title, by "Washer/Dryer" I read Washer and/or/xor Dryer.
I picked up this thread along the way because it was the latter that helped me and the information was there.

I'll know next time, but thanks for the help.

[stj]

because it confuses people - you should have started a new thread.

[hugokernel]

title said "washer/dryer" ??

Same board, same components, why can't I benefit from/exchange information?

[stj]

title said "washer/dryer" ??

[hugokernel]

did you change the top related capacitors?

Capacitors tested and ok.

The big one (330uf) has an ESR of ~1Ω.

and did you spin the blower by hand to check the bearings?

From what I've read, I would have done it if it was a dryer model, but it's just a wash version.

i think i know the answer to both
always start with the simple stuff - dont go breaking out thermal imagers or arduino's on the first try!

I didn't change the brushless driver to play I did it because it was burnt out (thanks to lotas for the explanation).

[stj]

did you change the top related capacitors?
and did you spin the blower by hand to check the bearings?
i think i know the answer to both
always start with the simple stuff - dont go breaking out thermal imagers or arduino's on the first try!

[hugokernel]

Small update, I finally received the Mutsibishi PS21964-4S motor driver and proceeded with the change, I also changed the TOP246YN.

A few solderings later, I reconnected the whole thing: it worked again, great joy, but after 24h of operation, the machine stopped during the end of a cycle (I suppose spinning/drying).

After dismantling, the TOP246YN literally exploded.

When I reassembled the TOP246, as I no longer had a thermal tab, I used a double thermal face for the connection between the TOP and the radiator, perhaps this was a bad idea.
I've read the feedback about replacing the TOP246 with a TOP248 (with resistor in series), so I'm going to try that as well as using good thermal paste.

[hugokernel]

I did a few tests earlier, put everything back in place (TOP246 and other components removed for testing) then plugged everything back in.
Result: Nothing happens when I press the button on the machine (although I'm not really sure, perhaps a relay has been activated).

In a nutshell:
The initial problem was that the power resistor linked to the ignition burned immediately when the Power button was pressed.
After removing the motor driver, it turned out to be short-circuited.
I repeated the test without the driver fitted, and nothing happened.

Maybe the TOP246 didn't really appreciate it and should be changed.

What can you deduce from this?

Thanks for your advice.

[hugokernel]

Re: LG Washer/Dryer Power Fail

Your module is faulty, it has three phases for powering the motor and two of its phases are broken, there is a short circuit on three IGBT transistors.

Ok, thanks for the answer!

I'll try to reconnect the washing machine without the motor driver to see if the machine turns on.

[lotas]

Re: LG Washer/Dryer Power Fail

Your module is faulty, it has three phases for powering the motor and two of its phases are broken, there is a short circuit on three IGBT transistors.

[hugokernel]

Re: LG Washer/Dryer Power Fail

Then you can also take a bite, just do not bend the module itself too much here and there, so as not to damage the heels where it is sealed, then each remaining pin will be easy to unsolder and install a new module.

Removing component success, thx.

The reference of the motor driver is PS21964-4S Mutsibishi Electric (datasheet: Datasheet)

There is electrical continuity between all the points in red.



Correct me if I'm wrong but I think there's a nice internal short circuit?

[lotas]

Re: LG Washer/Dryer Power Fail

Then you can also take a bite, just do not bend the module itself too much here and there, so as not to damage the heels where it is sealed, then each remaining pin will be easy to unsolder and install a new module.

[lotas]

Re: LG Washer/Dryer Power Fail

Carefully bite off the legs on one side with thin nippers and tilt them onto the top of the driver and there will be a marking on the other side.

[hugokernel]

Re: LG Washer/Dryer Power Fail

The short is most likely in the module (motor driver) under the radiator, check the resistance on the power capacitor.

Hi,

Thank you for your answers.

I just checked the motor driver and apparently, the problem come from it.

All the points in red are shorted and connected to ground, so it looks like the driver is dead.

Does anyone know the reference number of this driver (I didn't see any reference, wasn't sure I'd be able to desolder it, and wanted to make sure I could get one before venturing any further.)?

[lotas]

Re: LG Washer/Dryer Power Fail

The short is most likely in the module (motor driver) under the radiator, check the resistance on the power capacitor.

[CapLeaker]

Re: LG Washer/Dryer Power Fail

post some straight shot, high resolution pictures. So we can see something. for a 5w resistor to fail, there has to be a dead short somewhere.

[hugokernel]

Re: LG Washer/Dryer Power Fail

check the relays for burned contacts or open coils

The relay coil seems to be good (150 ohms measured, same value for the other 2 relays)

[stj]

Re: LG Washer/Dryer Power Fail

check the relays for burned contacts or open coils

[hugokernel]

Re: LG Washer/Dryer Power Fail

Hi,

I'm currently trying to repair a LG Washer F12952WH (sell on the french market 10 years ago), power board is EBR65873657 / EAX61526804.

The symptoms are simple: nothing happens when the button is pressed, after disassembling the power board (ref EBR65873657), I noticed that the fuse (220V, 8A) had blown and the power resistor (10 Ohms, 5W) used in series with the ignition button is dead.

I changed the 2 but when I press the ignition button, the resistor burns out immediately.

After going through this whole thread and looking at a lot of repairs, reading a lot of comments (https://www.youtube.com/watch?app=desktop&v=uCxA34JIJWQ, https://www.youtube.com/watch? v=CBWepvnvET8), I have unsoldered the TOP246 in order to test it, I have the feeling that it is not out of order (no short-circuit on its pins), moreover, I have put back a power resistor with a higher value (47k Ohms) and I have connected only the 2 connectors (the 2 colored ones), when I press the ignition button, the resistor heats up strongly (even though the TOP246 is not present).

My guess is that because the TOP246 isn't present, and therefore there's no power supply to the control electronics, the ignition relay doesn't switch on, and so the current the washing machine needs passes through the power resistor, causing it to heat up and destroy itself.

I have 2 theories:
- The TOP246 is out of order
- One of the main relay is out of order

Do you have any advice on this?
Thank you in advance.

[redwire]

Re: LG Washer/Dryer Power Fail

OK good just for anyone else who needs to fix an LG combo washer dryer model 1480YDS.
You were really thorough with the repair and have some good data.
So expensive to just toss them out and replace them over a few underrated semi's that are the problem.