LG Washer Dryer dead

[Markkk]

Hi, I have a LG washer dryer, model number F1480YD, approx. 6 years old, which has become completely lifeless.

It had been working fine until a few days ago when I tried to open the door when the machine was still in a cooling down phase at the end of a drying cycle.

The door would not open because the interlock prevented its opening while the machine was still on. I must have done this dozens of times in the past with no harm done but on this occasion there was a "popping" sound from inside the machine, the entire front panel display (every led) briefly lit up and then went off. Since then the machine appears to be completely dead.

I have done all the basic checks - socket, plug, fuse - all ok.

I have taken the lid off and followed the mains wiring to a large fuse on the right hand side of the machine - checked with a continuity tester - also OK.

I have removed the main PCB (from under the drum) and it appears to be OK, no obvious visible signs of burnt components. There is another fuse on this PCB - also checks out OK.

Does anyone recognise these symptoms? Is the interlock faulty? Is it the main PCB? Has a faulty interlock maybe damaged the main PCB? Is it something else entirely?

Any help gratefully received.

Mark.

 

[Whitegoodshelp (Andy)]

I wouldn't have though trying to open the door whilst it is still locked could cause anything to short out. Maybe the door lock was already going faulty. I would initially suspect the door lock. If the door lock has shorted out you may hopefully be able to smell something if you remove it and have a good sniff. It could potentially have damaged other components but not necessarily. It's also possible something else popped, and it's nothing to do with the door lock or the door lock has shorted because of another short somewhere else.

The first thing would be to remove the door lock and see if you can smell anything burned out in there. I have some articles that might help understand the door locks and how they work - Different types of door interlocks | How does a washing machine door interlock work?

[Markkk]

Many thanks for your reply Andy.

I have removed the door lock - no sign or smell of burning - I checked the reistance between the 4 terminals labelled 2, 3, 4, 5 (no sign of 1!):

5 - o/c to all other terminals

4 to 3 - 211 ohms

4 to 2 - 1150 ohms

3 to 2 - 1360 ohms

No idea what they are supposed to be - can't find any tech help on the LG website and the LG helpline just want you to order an engineer call-out.

I have checked continuity from the plug to the main PCB - live and neutral are both present on 2-pin connectors to the board although, curiously, live on one connector and neutral on two other connectors. There is no sign of any burning or other damage on the PCB......

I guess there's no way of checking out the PCB except by swapping for a new one...

 

 

[Whitegoodshelp (Andy)]

The door lock and short out and go with a bang. But normally power wouldn't totally stop at the door lock. If one is faulty the machine should still switch on and control panel light up. The symptom would just be that the machine won't start. If a washing machine is totally dead, and all the basics such as wall socket and fuse in plug are OK that leaves several other possibilities such as mains cable, mains suppressor (careful they can hold a charge), main PCB. Check my article in case it helps Washing Machine Won’t Start (dead)

Have you checked live and neutral through the on off switch? Could the mains suppressor have popped?

[Whitegoodshelp (Andy)]

Also check no wires in the wiring harness have been caught and been cut through or slowly rubbed on something and flashed and broken connections.

[Markkk]

Thank you Andy, yes, I have checked out the articles for dead machine and door interlock - both very helpful.

Mains cable and suppressor (filter?) all check out although, confusingly, the connector after the filter has live on blue and neutral on brown! (connector only fits one way round).

I checked the resistance of both heaters - 27 ohms for the washer, 35 ohms for the dryer. Also checked the motor - 8.5 ohms between any pair of  terminals.

I removed the front control PCBs andI reconnected the door lock and connected to the mains just to check for voltages on the control PCBs - they seemed very low - approx. 250mV - so there seems to be continuity but surely not enough volts to power the control panels?!

I will continue to check for broken wires.

Thanks again