Need to know what is the root of this Hisense WFU7012 washing machine problem

Thread Starter

Seabear123

Joined Nov 8, 2020
5
I have this washing machine from Hisense for over a year now and have been using it with no problems at all. Last day I wanted to use the machine. As usual I did what I do, but this time when I pressed the power button to turn it, something blew up inside it and electricity was cut off from the whole house. I restored electricity and tried to turn on the machine again but no hope. So I opened the machine and was able to determine that fuses has blown up in the main control board.
I can purchase the board and replace the damaged one, but before I do that I suspect that another problem could be causing the issue and therefore may damage the new board, so I am looking for suggestions for what could have caused the problem to occur.
 

MrChips

Joined Oct 2, 2009
23,086
Welcome to AAC!

Model number of washing machine?
Type of washing machine? Dishwasher? Clothes washer? Power washer?
Picture of the board?
 

Thread Starter

Seabear123

Joined Nov 8, 2020
5
Did a wired fuse blow? Or an RCD (earth leakage detector) trip? Or a circuit-breaker trip?
I appreciate your answer.
what did actually happen is : I saw a faint light flash that appeared as i hit the power button and the circuit breaker tripped at the same time .
from what i could seen after opening the machine , it seems that a fuse in the PCB has blown up and burn marks could be seen around it , as well as on the opposite plastic cover.
I can't post any photos as it has not crossed my mind to take an actual photo of the board , maybe because i was still in shock. sorry first time something like this happened to me in person.
I'm actually searching for possible causes as i want to fix this problem from the root. I have already ordered a replacement PCB but i still have some suspicions that this problem might happen again if the main cause is not fixed. what do you guys actually think happened or caused this problem ? can it happen again or not ? what do you suggest to prevent such event form happening again ?
 

MrChips

Joined Oct 2, 2009
23,086
For the house panel main breaker to trip something catastrophic have had to happen.
There are lower current fuses/breakers that should have tripped before that to happen.
1) The washer fuses should have blown first.
2) The breaker servicing the washer should have tripped before the main breaker.

Granted, a short in the washer triggered the power outage. Why the main breaker in the service panel tripped is a mystery. I would suggest that you get a qualified electrician to take a look at your service panel. What is the current rating on the main breaker and on the line servicing the washer?

For the WFU7012 to blow its fuses, there must have been a high current draw from the AC mains supply, and large enough to trip the main breaker.

I cannot see where the fuses are located in the diagrams below. A short could have occurred in the SMPS or a fault in the control board causing multiple loads to be energized at the same time.

Sorry to say, there is a possibility that the fault may still remain even when a board is replaced. You need to seek more experience advice on this.
Hisense WFU7012_2.jpg

Hisense WFU7012_1.jpg
 

Thread Starter

Seabear123

Joined Nov 8, 2020
5
Thank you for your answer as well.
I searched for an image on the internet in order to make things a little bit clear. i don't know if this would be helpful or not.
What actually happened : After the whole washing machine event , The main breaker tripped along with the breaker servicing the washer at the same time, then i have tried to raise both of them. i have raised the main breaker without any problems but the breaker servicing the machine tripped twice before i could raise it without disconnecting the washing machine ( stupid move perhaps ).
 

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Thread Starter

Seabear123

Joined Nov 8, 2020
5
Ok do you have a DVM, if so unplug the washer and measure the resistance between Live and Earth and Live and Neutral.
I appreciate your help.
But what difference would that make ? i mean what are you thinking about ? sry. if i sound like a total noob .
 
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