On Fri, 09 Oct 2020 21:08:30 -0400, legg wrote:

snip

I know Schottky diodes have fast switching times (and a low forward
voltage drop but not sure if that would be relevant here?) so is a
Schottky required in what I think might be part of a 'charge pump'
circuit because of the frequency of the output through the SMPSU and
assuming I decoded the markings correctly, why would it need a 1000V
device there?


Output rectifiers of simple wide-range input flybacks
will tend to see voltages stresses unrelated to the
output voltage.

Ah, ok.

At the same time, HV diodes will be relatively inefficient,
due to slow speed and high Vf.

Check.

If you can find real info on the part, it'll be easier to make
a safe replacement.

checks diode again with better light and loupe Ah, it's an SR2200 JF
(not SJ220, that was a result of my dyslexia g) that looks to be a
200V 2A Schottky Barrier Diode.

https://www.4project.co.il/product/210423

Seeing as the original part failed, it
would be unwise to skimp on any of it's intended ratings.

Understood, I'll get the right thing ordered now.

Cheers T i m