Whirlpool ATF8000FS clothes washer user control board varistor VDR4 identification

[Bob F]

Washing machine began flashing many LEDs and beeping every second. VDR4
is burned black, C26(22uF 200V) and C27(10uF 200V) are bulging.
Can anyone help identify that VDR? It is a vertical disk about 5/16" in
diameter, with about 1/4" lead spacing. One lead of it goes to the (-)
side of both bad caps.

My guess is the caps failed, blowing the VDR, requiring replacement of
those. Other opinions are welcome.

There are 3 other VDRs on the board which are near each other but not
near VDR4. These are labeled K2759U, but I have not found a proper
datasheet for those.

ATF8000FS machine
PC board #EL1345526
plastic case labeled 134847902
Online search brings up 137007000NH as the assembly.

[Peter W.]

1 (866) 698-2538
www.whirlpoolcorp.com/wp-content/uploads/Whirlpool...

[ehsjr]

The K2759U is a 275 volt MOV (aka VDR - Voltage Dependent Resistor).
The full part number is LIKELY S10k275. A probable(*) replacement
part is Digikey 495-1433-ND.

* = I say probable because that is what I would try if it were
my machine - based only on the information you posted, which
includes (on my part) the assumption that the burned VDR is
identical to the other VDRs. Of course with a schematic or
reverse engineering we'd be in much better shape to make a firm
diagnosis, but lacking that you have to go with what is
likely but not proven.

As you undoubtedly know (but others might not) you have to
replace those bulging caps, too.

Good luck with the repair!
Ed

[Bob F]

On 2/11/2024 12:16 AM, Bob F wrote:
> Washing machine began flashing many LEDs and beeping every second. VDR4
> is burned black, C26(22uF 200V) and C27(10uF 200V) are bulging.
> Can anyone help identify that VDR? It is a vertical disk about 5/16" in
> diameter, with about 1/4" lead spacing. One lead of it goes to the (-)
> side of both bad caps.
>
> My guess is the caps failed, blowing the VDR, requiring replacement of
> those. Other opinions are welcome.
>
> There are 3 other VDRs on the board which are near each other but not
> near VDR4. These are labeled K2759U, but I have not found a proper
> datasheet for those.

07 K2759u 07 21 is the full label on those 3.

[Bob F]

I really appreciate this response. Now I have something to work with.

[whit3rd]

On Sunday, February 11, 2024 at 12:16:45 AM UTC-8, Bob F wrote:
> Washing machine began flashing many LEDs and beeping every second. VDR4
> is burned black, C26(22uF 200V) and C27(10uF 200V) are bulging.
> Can anyone help identify that VDR?

If the 'VDR' is blown, there was maybe a voltage surge; check
the voltage at the plug.
If that "VDR" is an MOV, the capacitors were the victims of a surge,
and between AC and capacitors is rectifiers; you want to replace
the capacitors, and check the rectifiers.

[Bob F]

Thanks for that. The diodes check out OK. Digikey has already shipped
the MOV's and caps.

I hope the surge did not take out other parts that do not show damage.

My thought was that the caps could have failed from age, or the bad cap
syndrome from years ago, and that allowed surges to overpower the MOV.

[Bob F]

I replaced the 2 caps and burned varistor with parts from Digikey. After
re-assembly, it powered up perfectly, and is now doing the first load of
laundry.

VDR4 Varistor Digikey #495-1433-ND
C26 22uF Cap Digikey #493-4803-1-ND
C27 10uF Cap Digikey #1189-1175-ND

[ehsjr]

Great! Congratulations!

[Tim R]

Is there a point at which you give up and program an Arduino or similar? Just curious. My washer (1990 purchase) doesn't have any electronics and I've thought of doing that if the timer would ever fail - or maybe just a box full of toggle switches.