On Mon, 17 May 2021 15:47:30 -0500, Chuck
wrote:

snip

Replace small electros on primary side,

The ones near C18? (just for reference, C16 is 100uF, 25V and C17 is
4.7uF, 50V). I have one of those automatic component testers. Would an
'ok' from one of those be ok?

snip

To test C16 and 17 you would need an ESR tester.

Yes, I have one. Of the 4 x 1000uF smoothing caps across the output
(where one had blown) 3 had an ESR around 0.1 and the blown one a
touch higher? Is that right / normal (FWIW they also showed a Vloss of
~2% and were all around 1100uF)? [1]

It is a pretty good
bet that both are bad.

Ok, I'll pull test / replace those next.

Make sure that you use 105C caps.

Check (I did so with the 4 smoothing caps, but didn't check the lead
spacing on my order (doh)).

Cheers, T i m

[1] Could it be bulging because it just happened to be the closest to
the output choke and that had been running fairly hot, rather than it
had failed by drying out or whatever? (they were nichicon 105 1000uF
16V YV(M) H1305)