More data on dead wall wart

From: Tony Duell <ard_at_p850ug1.demon.co.uk>
Date: Thu Dec 9 19:18:00 2004

>
>
> So I double checked the AC voltage output on this TI wall wart for the
> Silent 700 model 703 and it definitely has no voltage (and correction on
> my meter settings: it has 200VAC and 600VAC).
>
> I also checked and there is infinite resistance between any combination
> of pins (I checked on all settings from 2 ohms to 20 Mohms). For the hell
> of it I checked for DC voltage and there also is none.

On both the primary (between the mains plug live and neutral pins) and
secondary (between the output connector pins)? That is unusual, it would
appear you have at least 2 fualts. You are sure your meter is working
properly?

>
> Foo.
>
> Next step is to crack it open. Anyone know a good way to open up these
> permanently sealed transformers?

I've found puttling a flat, and fairly blunt 'blade' (the edge of a metal
strip, for example) along the obvious joint in the case and then tapping
it with a light hammer works quite well. Don't try oprise the joint
apart, you will mark the case. You're trying to crack the glue bond.

That works for dismandling the HP calculator (classic, topcat) battery
packs too.

-tony
Received on Thu Dec 09 2004 - 19:18:00 GMT