Transformer "lost" in ceiling

[Rad1o]

In our shower en-suite two of the 12V halogens have stopped working. 3 others still work. The bulbs are fine.
We had this bathroom done about 14 years ago. I remember talking to the electrician about the transformers, but not where he fitted them. The bathroom installer put another plasterboard under the existing plasterboard ceiling to make it look nicer once plastered, so we have about 20 - 25mm of plasterboard ceiling.
I had a look in the ceiling and located one transfromer for the still functioning 3 halogen lights and a junction box from which the electrician has fed the one transformer.
I had a look with a "simple" inspection camera which allows to be bent into shape and the pushed into the ceiling voind. I cannot flex the tip remotely. Even that way I could not locate the missing transformer.
Above the bathroom is a fairly shallow pitched roof which used to be flat roof, so no access into the roof space.

I have found wire tracers online and wondered whether they would be any good to trace a wire through 25 mm of plasterboard?
Any other ideas or recommendations other than the hammer?

 

[sparkwright]

Is there something like a fan on the ceiling, that could be removed, and the transformer hidden above that?

It would be a poor design to have a transformer that cannot be accessed without damaging the ceiling.

 

[Harry Bloomfield]

I have found wire tracers online and wondered whether they would be any good to trace a wire through 25 mm of plasterboard?
Any other ideas or recommendations other than the hammer?

No that wouldn't work. Could you not take down the two none working lights and see which way their cables head, follow them.

 

[oldbutnotdead]

Is the transformer you have found fixed down or just floating in the ceiling void? If it's floating then good odds the other one is as well, drop the non- working fittings out of the ceiling (power off obviously) and gently pull the cable on one, see what you can feel. With luck you'll feel a bit of resistance and hear trx and jb rattling towards you.
EDIT If the cables go tight, you should be able to get a position for the trx by looking at the angle of the tight cables And then probably hammer time.....

 

[Rad1o]

Thanks for the replies.
It is done. Found the transformer. My wife - very small hands - was in the ceiling again. The first time she could only fell what I saw with the endoscope. Then we pulled on the affected wires and figured which ones ended in the drill holes through the joists and follwed them to a transformer. The whole forearm was in the ceiling and I just hoped she would not slip off the ladder. That would have been like the hammer job. It was tucked behind and under the junction box and only just had enough cable to drop out.