How do you replace the power button on LG WT-H800 washer?
Modern washers and dryers, and this one is no exception, use a control panel that is a plastic overlay over domed touch buttons. Sometimes these plastic overlays will also have clear windows that allow LED indicators to shine through as well.
The LEDs and touch switch domes are all mounted onto a circuit board that is part of a sandwich comprised of the overlay, the circuit board and possibly also a metal or hard plastic rear support plate.
Common types of failure of the touch dome switches are:
- The domes become intermittent and will not reliably register with the internal microprocessor to invoke the desired function.
- The domes lose their springiness and collapse so that they no longer operate as a touch button.
- Sometimes the plastic overlay material cracks around the most often used buttons. A complete piece of the plastic will often come away leaving the underlying circuitry exposed.
Unfortunately the fix for bad or broken touch buttons is to replace the whole control panel assembly. This is often not a welcome option because the part can be quite expensive. But it is really the only way to restore the function and appearance of the original product.
Some electronics technician or hobbyist or engineer could possibly replace a broken touch button with a discrete push button switch. However that type of fix will always look like a kludge even though it may actually function okay.
I just did this -- sorry I don't have pictures. If you have not lost your power button, but it has merely broken, you can carefully put it back into place:
The power button is attached to a long flexible lever with two holes in its end.
At assembly, these fit over two plastic posts coming off a bigger post, and heat-riveted, so the lever is riveted to the plastic panel at one end for registration, goes over a fulcrum for springiness, and has a post behind the button that hits the actual microswitch.
You can replace the two plastic posts with miniature watch screws. You will need a micro-size drill bit to drill pilot holes, and this is a delicate operation. I also tied and glued the whole assembly together, and it works fine now.
As Michael said the usual solution is to pay a surprisingly large sum to a repair engineer to replace the circuit board (PCB).
If A) the PCB uses discrete switches and B) you have the right tools and experience -- you can spend a few cents and attempt a repair.
However, many consumer goods have control panel switching mechanisms that are not repairable. For example, they might have a flexible membrane over a printed contact array.
How to replace a push button switch for a fraction of the control board cost. Warning not responsible to additional damage/injury caused by these instructions. They are simply a guide on reverse engineering your washing machine BECAUSE A SWITCH IS LESS THAN 20 DOLLARS WITH SHIPPING NOT $300 FOR A WHOLE DANG BOARD
Step 1: Dissamble washing machine until you have the control board in front of you.
Step 2 find the power button, Note it's orientation and find out what kind of switch your working with. Sometimes it's just the plastic overlay that's broken the switch underneath is ok. It is usually a push button switch Now here comes the hard part finding out what type. A lot of these smaller parts don't have readable part numbers and finding the exact replacement may be hard. Furthermore if the plastic covering it is cracked/broken your washer will never look the same again. That's ok we can still make it work just fine. You will need a solder iron, solder, wires, and an ohm meter preferably a fluke. Desolder the component (heat up all the contacts simutaneasly until the part becomes loose and you can pull it out, or if you have braid you can use it to suck up solder for easier removal). I suggest you remain grounded and have the board detached from all power sources. If you can find an exact replacement great. Simply put the new switch in with the exact same orienation as the original and solder it to the board (heat it up with the iron and add solder until it is nice and shiny and covering the board and contact but not too much).
Step 2.5 Sometime you can find an exact replacement. In this case you have to figure out what type of switch it Note which contacts are connected and which are open. This will be 0 or infinite resistance though usually it beeps when it's connected/short. Depress the button and note how the contacts change. The goal is to determine it is a momemtary switch, singe pull singe throw. or double pull double throw. This may be a bit of confusing and will require research. Your goal is to find the same style switch and use it as a frankenstein replacement. This will require solder wires in the place of the switch on the board to use as a connector and wrapping it with electrical tape to keep it insulated. I suggest taping it to the top/side of the machine and refrain from place clothes on top of your washer to avoid a short.
Step 3 reassemble the machine and plug it in. Time to see whether you did it correct or ruined the rest of the control board. If it doesn't light up when powered on, sparks when you plug it in and/or smokes, or is just plain unsafe. Bite the bullet and replace the whole board.
STEP X BE CAREFUL THIS WILL BREAK A LOT EASIER