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Comment by crispyambulance | Hacker News Reader

I don't believe it-- at least not the claim that it's actually "washing machines".

Has anyone ever looked at washing machine PCB's?

They're conformally coated with silicone. The whole control board with "the brains" is dipped into goo to protect it from the harsh, wet environment of a washer. The effect is that it makes component-level repair, let alone part-harvesting, intractable.

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In the past three years I've repaired two washing machines whose main PCBs were not coated (neither were they broken, the washaing machines were defective elsewhere). One was a Beko, so more on the cheap side, and one was some Aldi-branded Italian make I haven't heard of before. I think the name was Whirlpool. It was extremely cheap and the connectors burned after a few years of use, taking the main PCB down with them. But even the replacement part was not coated.

I think only the more upscale or expensive ones are coated for longevity.

Whirlpool is not "some Aldi-branded Italian make", it's an extremely common American white goods producer. They used to be well-known for the robustness of their machines.

Your comment made me curious, so I looked into my old photos. It seems I was mistaken, it's been a few years. It's not a Whirpool but simple a "WM 25E" ("WM" probably for washing machine). Apparently the same model is also branded as "Elin WM 25E".

This forum thread [1] show the exact PCB that burned out in my machine, I've bought the replacement on ebay back then. There was some motorola µc on it and several run of the mill components, but no adhesive or "goo".

[1]: https://elektrotanya.com/content/elin-wm-25e-q2-keresese#

Meh, the Whirlpool of today may be different. Most of these manufacturers ended up in a race to the bottom for making cheap e-waste.

That's why I said they used to be well-known for it, I don't really know much about them today. But either way, Whirlpool is American, not German-Italian.

It seems I was mistaken, I replied on your other comment as well. It's been a few years since I fixed that specific model. The burned PCB was by a manufacturer called Minisel, and I think variants of Minisel control units are used in many cheap washing machines like Beko, Bauknecht, Elin, Whirpool and probably other. Maybe that's why I confused the brands. Ebay ist still full of these units [1].

[1]: https://www.ebay.de/sch/i.html?_nkw=minisel&_sacat=0

>Whirlpool

Whirlpool is a major US brand of appliances.

Earlier in my career I was working on components of undersea seismic nodes that were both conformal coated and potted in epoxy. Along the way we realized we were going to have to make a blue wire mod to the PCBs already deployed or loose quite a bit of money. We developed processes to rework these PCBs very effectively, although I can not reveal details. Suffice it to say it was not a fun process, but it was deemed necessary.

Sometimes when all your solutions are bad, you just have to pick the least bad solution. It's still not a good solution, but not solving it is worse. If it is the only available device they know of with the chip they need, they might not have another option.

Not sure if that's a regional thing - I've taken mine apart a few times to repair various things, and the electronics aren't coated in anything (UK)

That's interesting. The Samsung's I've services have had conformal coating on the "mainboard". This is the board that has the relays. The board directly behind the control panel has been without coating, but that was just LED's and some switches.

Must vary from manufacturer to manufacturer - this is a Bosch that's now coming up to about 11 years old, and thankfully still going strong after a temperature sensor and heating element swap a few years ago.

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