Bosch SPS40E22GB/28 dead

[washingmachinewoman]

No sign of life at all.
Customer has replaced the on/off switch and checked the mains lead to no avail.
Am I right in thinking that as the mains lead goes directly into the PCB, it’s likely the PCB has blown? If so, how do I go about finding out which component has gone?

[electrofix]

yes mains lead goes into board

assume socket has been checked

pull the board and look for power supply damage. there will be an inrush resistor, under 100 ohms. find it and see if its blown

Dave

[washingmachinewoman]

Brilliant, will do.

Lucie

[washingmachinewoman]

So I had a look at the board, and the problem was this:

https://1drv.ms/u/s!As5kxZz8xEnsl1f1R6NGaPyjNW3M

One seriously fried small slug 😮
As far as I can tell the inrush current resistor was good.
I removed it and carefully scraped off as much as I could of the dried slime, but problem persists. So sending the board to QER to see if it can be cleaned and fixed.

Lucie

[washingmachinewoman]

Update
QER thinks the main chip has blown. I got it back – now have a board to practice on.
Ordered a new one but not in stock at the manufacturer, earliest despatch in a couple of weeks. Thankfully customer is not desperate and quite relaxed about it.

Lucie

[electrofix]

the fact the chip has gone does not suprise me as its shorted the triac gate lines with mains

Dave

[iadom]

Was going to say slug damage whilst your image was loading. It was quite common on these.:(

[adv]

How can you get slugs in your kitchen ? :rolleyes:​​​​​​

[washingmachinewoman]

They get through incredibly small gaps…

[iadom]

They can even sneak in on the bottom of your shoes or boots.

[Author]

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