Ansmann Energy 16 PSU

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

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

I have one similar. Yes, they are impressively clever for the money. By they do not do ICs, only generic components. The only component that I found will fool it, was a germanium power transistor. The low Vbe, combined with the low DC gain probably threw it off.

Hard to say. There are so many factors that affect the aging of caps. It does not take many seconds to take them out and test them, though.

Yes, I noticed that, too. Hopefully, the TOP does not get all that hot.

Aren't they. ;-)

My only thought was that whist the TOP is actually a 'clever' 3 pin device, there may be some basic logic that it could respond to that might make the tester think it was a working FET or Triac or some such? eg. You might be able to use it as a go / no-go test, *if* it detected something positive (however misdirected) in comparison to a good one?

Ok ... and that's not even a 'clever' component at such. eh. ;-)

True, as whatever 'glue' they used to hold stuff down seems to have gone off a bit in any case. Maybe I'll replace the diodes first and if the unit then works, treat it to a fair of quality (low ESR?) caps at that point.

I doubt it would (for that heatsink) as it's got next to no radiative qualities (being partially masked by the cap) and only a small thermal mass. It might just be there to rest the cap on. ;-)

Cheers, T i m