On Sun, 30 Jul 2017 12:21:53 +0200, Robert Roland
wrote:

On Sat, 29 Jul 2017 21:22:53 +0100, T i m wrote:

Would you think one of those component testers would be able to
identify the PWM reg, at least with a go/no-go result?

I do not know which component tester you are talking about, but I
would be very impressed if it could.

Well, whilst I think they are 'quite clever' I agree that it probably
couldn't test the TOP223Y's.

http://www.eetimes.com/author.asp?se...doc_id=1329331

I bought one (ironically) for measuring the ESR on SMPS caps (Topfield
STB) but have used it (mostly successfully) for many other things
since. ;-)

On that ... do you think it might be worth testing (or even just
replacing) the two main caps in case they are getting weak? I note
they have an extra heat shrink 'skin', probably because they are
pressed up against the tiny heatsink on the TOP223Y's?

Cheers, T i m