Someone let the smoke out (not just another cap!)

[dropkick]

Went to my parents' house and smelled burning PCB as soon as I opened the door.  Started eyeing all the cheap LED lightbulbs around, TVs, and other electronics  but they seemed ok.  Found this smoldering mess in the kitchen!  This dishwasher was still faithfully running and drained after pushing cancel--I was expecting a flood.  After that it wouldn't shut off although the cancel function still responded!  One terminal burned clear through and came off in the connector. Suprisingly that thermal fuse on the left which lived in the notch in the board didn't open. Great safety feature!

[floobydust]

  Good you caught it, the thermal fuse is usually a mile away from the bonfire...

There are a few recalls for dishwashers causing fires. Check with Whirlpool and CPSC. Other brands are just as dangerous- GE, Kenmore, Maytag, Kitchen Aid, Bosch etc.
I've seen bad pcb design: power relay pins breaking soldering joints and not enough copper making a hot spot, a connector that melted, creepage/clearance spacings violations etc. that cause insulation to break down and carbon track.

[amyk]

I wonder how it started. Moisture? The lack of conformal coating is disappointing.

[floobydust]

Newer versions of the control board (Whirlpool WP8564543) have slots cutout between the spade connectors, so I would say they had a bad pcb design (for this WP8267371) with creepage issues. The motor is inductive and back EMF can be sustantial and MOV's for that... well they cost cost the moon.
It's that or hot spots on the pcb due to poor connections - at the high current connectors (heater) , or fractured solder joints at the relay pins etc.

"If your dishwasher is ten years old or less and you recently experienced a control board overheating event, please call Whirlpool directly at 1-877-559-2515 to discuss relief potentially available to you. If you qualify, you will receive a minimum of $100 cash or 30% off your choice of a new KitchenAid, Kenmore, or Whirlpool dishwasher."
https://www.dishwashersettlement.com/home.aspx

Whirlpool Settles Dishwasher Fire Lawsuit With Offer of Rebates and Repairs

[wasyoungonce]

Well done Flobby nice post.....bloody mfgrs...screw it up and then leave you adrift...but hey $100 off next purchase....yeah right....as if you would want to touch them again...

To coin a phrase, one burnt.....twice afraid......hahaha

https://www.whirlpoolcorp.com/dishwasher-safety/

https://www.consumerreports.org/dishwashers/whirlpool-settles-dishwasher-fire-lawsuit-with-offer-of-rebates-and-repairs/

[dropkick]

Looks like we're outside of the window for the $100. Gee thanks.  I see the lawyers got $4000 per class member however!

Didn't see much evidence of long term heating of the wires. Only damage to the connector looks to be from the final meltdown. So yeah poor PCB or solder joints. Maybe its just me but I'm always leery of high amperage or spikey things on circuit boards. I know... math and it "should work" but still   Mounting external relays would cost what 5 bucks and that's just not accepetable!

There's a small gasket around the front panel of the door where this thing sits but we've all seen the steam that pours out of these things. You know its getting in thru latches and handles etc.

Now to see how many replacement machines are "stuck in the supply chain." So they say!

[Haenk]

Mounting external relays would cost what 5 bucks and that's just not accepetable!

If they can use a shorter screw or even could leave out that screw, that's certainly done, if it's good enough for the warranty period. An additional 5 USD/EUR in parts is completely insane, that will never happen.

Considering the vibration and moisture, one should even wonder how they get along with such shoddy electronics.