On Sat, 10 Oct 2020 03:49:20 -0700 (PDT), "
wrote:
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Assuming the spec I looked up was correct, and it was a 2A device, and
the PSU itself was rated as 400mA, I wouldn't have thought straight
current would have taken it out so would there me a recommended 'safe'
startup procedure that might put the least shock load on the diode?


400ma is the maximum continuous duty design output, but during the first few cycles, it's essentially feeding a short circuit until the filter caps charge.

Understood.

Most modern smps circuits ramp up the drive in a controlled manner using a slow or soft start strategy to mitigate that.

This is the PSU OOI: https://ibb.co/VtBY4Rt

The IC is a CR6338T.

Still, sometimes diodes just short, and I've seen more random Schottky failures than other types.

Oh, ok.

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I wouldn't worry about the start up procedure unless there are specific instructions to the contrary. Consumer electronics are generally designed to be plug and play regardless of the sequence.

Agreed, I was just thinking that this being a 'cheap and cheerful'
example of this sort of thing, if they may have cut more corners than
more expensive brands might, making them slightly less 'durable' under
some circumstances ... how they handle the 'what if' situation?

But as you say, it could have just been one of those things and if it
works it could be fine till it's worn out. ;-)

Cheers, T i m