Front Load Washing Machine - Motor Control Board - Repeatedly burns out

Thread Starter

SunnyCoast

Joined Aug 29, 2018
4
Speed Queen #803255P motor control PCB

Burns out at the same spot every time. Now up to Board # 5. Several loud bangs.

Pic of a new board
Pic of my damaged board

The burn out usually occurs at an orange resistor right in the middle of the board. It melts or breaks into pieces.
I'm trying to find out what might be causing this problem. I do have the washing machine plugged into a single outlet surge protector.
Thanks for your help!
 

ArakelTheDragon

Joined Nov 18, 2016
1,353
Can you please tell us the following:

Does this happen only on 1 wahing machine?
What is the interval of time at which it happens?
Does it happen when you turn the machine on/off or when it is running normally?
Does it happen during a specific program of the washing machine or during a specific part of 1 program (high rotation cycle)?
Are there any transistors, capacitors, coils near the burned component?
Do you have the necessary skill to check (with a multimer) , replace the component and work with electricity?

Anything we say you can use/try/understand at your own risk.
 

Thread Starter

SunnyCoast

Joined Aug 29, 2018
4
Yes only on one machine. I have a backup machine which runs fine on the same power outlet. However it is an old style Hoover without the PCB board.

*The burnout occurs on the resistor labelled "RV7", located just below the heat sink

It occurs within a anywhere from a few washes to a couple of weeks worth of washers from after a board is replaced. The machine goes through an avg of 4 washes/day
The burnout occurs on a regular wash cycle.
Within a few minutes of the wash commencing. I cant recall if it is when water is filling the bowl or when the bowl is agitating
I have multimeter skills and can check.
Here's photos of several boards. One is more burnt then the other.

https://imageshack.com/a/img923/4062/vok636.jpg
https://imageshack.com/a/img923/4655/gQbZsx.jpg
https://imageshack.com/a/img921/9476/g2jbGc.jpg
https://imageshack.com/a/img924/7449/JSy4SD.jpg
https://imageshack.com/a/img924/1038/zNxSaN.jpg
https://imageshack.com/a/img922/20/JXKQnZ.jpg
https://imageshack.com/a/img923/7000/d5GZnH.jpg
https://imageshack.com/a/img924/9394/dRdmdc.jpg
https://imageshack.com/a/img924/8144/KB8hBn.jpg
https://imageshack.com/a/img921/4300/QRFnYJ.jpg

Agree with terms and conditions.
 

ArakelTheDragon

Joined Nov 18, 2016
1,353
There are 2 options:
The problem comes from the board, or the problem comes from the surroundings of the board.

Is it possible ot replace the resistor on 1 of the old boards and monitor its temperature, voltage and current. Maybe it is not with enough power dissipation and it burns. I can not open your pictures until I get home, but I will see the package of the resistor and check its power dissipation if possible.

In any case, the power surge through it is too high and it burns. Now we need to know, why is there more power than it can handle. The rest of the components are ok? If so, then the problem is from the resistor.
 

eddwhatley

Joined Sep 16, 2014
4
Sir SunnyCoast . . . . . .

In order to enable one to make a fuller initial analysis . . .aditionally . . . please supply the full identifier numbering of the
units HEAVILY heat sinked 3 phase motor driver I.C.. . .of which I can ONLY make out the initial IRAMS ? ? ? .
I can only assume it to be of the Int Rect . Infineon IRAMS10UP60A family group, until I am informed otherwise.
Please confirm.

73's de Edd
Just visiting . . . from . . . . .
https://www.electronicspoint.com/members/73s-de-edd.41129/
.....
 

Hymie

Joined Mar 30, 2018
991
RV is normally used to indicate a varistor.

The purpose of which is to limit circuit voltage spikes.

This would suggest your installation is experience excessive voltage spikes.

I would consider powering the machine via a surge suppressor lead such as this.

https://www.ebay.co.uk/itm/Masterpl...504125?hash=item3fa663e4bd:g:PtUAAOSw~xVbWfhF

or one suitable for the voltage at your location (not forgetting the current draw of the machine).

An additional thought, the varistor may be there to limit voltage spikes produced by the motor brushes arcing. If it is possible to operate the machine such that you can see the motor/brushes with a cover removed – you could observe if this might be the issue.

Might be time to change the motor brushes.
 
Last edited:

ebp

Joined Feb 8, 2018
2,332
Hymie, this is almost certainly a brushless motor control.

The varistor is far too small to have anything directly to do with the motor and there is only one, whereas other things are in threes. To blow one to kingdom come like that requires a gross overcurrent. I strongly suspect the failure is actually in the motor driver IC and the varistor is being killed in consequence. In one of the photos there is also a detonated capacitor.
 

Hymie

Joined Mar 30, 2018
991
I would conclude that the design of the PCB is at fault, creating such large voltage spikes that RV7 is unable to withstand them, and fails short circuit as a result.

The two most important parameters of a varistor are the clamping/working voltage and the energy they are able to withstand.
It is likely that the varistor is rated for your local mains voltage.
I suggest you get hold of the largest varistor you can fit (>20mm diameter), that the allowable space permits.

(the greater the varistor physical volume, the higher the pulse energy the device can withstand)
Should have added that you need to make this mod to a new working PCB.
 

Hymie

Joined Mar 30, 2018
991
If ebp is correct and it is the motor drive IC failing – and the problem is unique to this machine, then I would suspect an intermittent connection to the motor might be the cause. With the sudden loss of a load, the output drive voltage may go haywire for an instant (destroying the driver & varistor).

So it would be worth taking a close look at the plug connectors to the motor and check that all pins are located correctly within the shells (and not pushed back by mating, or making a poor contact for some other reason).
 

ArakelTheDragon

Joined Nov 18, 2016
1,353
I would conclude that the design of the PCB is at fault, creating such large voltage spikes that RV7 is unable to withstand them, and fails short circuit as a result.

The two most important parameters of a varistor are the clamping/working voltage and the energy they are able to withstand.
It is likely that the varistor is rated for your local mains voltage.
I suggest you get hold of the largest varistor you can fit (>20mm diameter), that the allowable space permits.

(the greater the varistor physical volume, the higher the pulse energy the device can withstand)
Should have added that you need to make this mod to a new working PCB.
That is not likely as it happens only on 1 machine and the PCB was replaced numerous times. The 2 options are: some other PCB (like you mentioned) is causing the problem or some other component. The last option is sabotage.

Also please check if there is a connection between the variastor and something unexpected, like the grounding or that some component on your other PCBs has burned and leads to this. I do not believe the problem is from the PCB itself.
 
That is not likely as it happens only on 1 machine and the PCB was replaced numerous times. The 2 options are: some other PCB (like you mentioned) is causing the problem or some other component. The last option is sabotage.

Also please check if there is a connection between the variastor and something unexpected, like the grounding or that some component on your other PCBs has burned and leads to this. I do not believe the problem is from the PCB itself.
Years ago, I had a friend's washer continue to trip the gfci after smelling. This was a "dumb" washer, but the real problem was the machine control was trying to run all the speeds at once. The culprit was in the device which set the wash cycles.
 
Speed Queen #803255P motor control PCB

Burns out at the same spot every time. Now up to Board # 5. Several loud bangs.

Pic of a new board
Pic of my damaged board

The burn out usually occurs at an orange resistor right in the middle of the board. It melts or breaks into pieces.
I'm trying to find out what might be causing this problem. I do have the washing machine plugged into a single outlet surge protector.
Thanks for your help!
Possible leak in the tub bearing area causing an electrical short? This video is about replacing the hall effect sensor, and leakage evidence was found it happens at the 1:45 point in the video :
 

abrsvc

Joined Jun 16, 2018
90
I am assuming that the large IC is on fact a IRAMS10UP60B which is a motor controller. I would suspect that there is a problem with the motor that is causing the IC to fail in such a way that the varistor is smoking. Check the motor. I believe that the motor should be a 3-phase motor controlled by that IC. Perhaps one winding is open/shorted?

I would not suspect a problem with the board at this time. Look outside of the board.

Dan
 
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