On 18/05/2019 11:44, D.M. Procida wrote:
I have an old B&D cordless drill; the batteries don't charge.

Either the batteries or the charger are faulty.

I've opened up the charger. At the input of the transformer, I measure
240V. At the output, 0V (I'd expect 18V or so).

I assume this means that the transformer itself is broken - at least, I
can't think that anything in the circuit after the transformer could be
responsible.

I haven't desoldered the transformer from the circuit board, but I guess
that would be a way of being sure.

Is that correct?

Daniele


If old iron cored transformer then it may have an embedded thermal fuse
in the primary winding. It's usually possible (if being careful) to cut
back the insulation and bypass said fuse - purely for testing purposes
of course.