I’ve got some track lighting in my hallway – 12v, Ikea’s finest, has worked fine for years. Then, the other day, it just stopped.

Previously, when a bulb has gone, its tripped the switch – this didn’t happen this time and the bulbs appear OK. I’ve also replaced the fuse in the 12v box once before so had a box of spares thanks to Maplins. I’ve tried a new fuse but this didn’t work.

So, what can I do to diagnose and hopefully fix the problem?
Do these things have limited shelf life and just expire at some point? (It must be 7 or 8 years old)

Could be the transformer has burned out. Have you access to a multimeter? Test the fuse first, sometimes they look OK but the fuse element has blown.
Would you be confident in opening the case with the power turned off and measuring the output voltage from the transformer?
Don’t take any risks if you’re unsure!

Would you be confident in opening the case with the power turned off and measuring the output voltage from the transformer?

Can I do that with a wet finger?

Don’t take any risks if you’re unsure!

Oh OK!

Wet fingers and standing barefoot in a basin of water is best 😉

Transformers do not last indefinitely. TBH getting 7-8 years from an Ikea unit is good going – it owes you nothing. 12V lamps are notoriously short lived and inefficient. If the tranny has failed you’d be better off scrapping the ELV track & going down the LED route – up to date lamps last years.
Assuming it’s a transformer with accessible pcbs, check input and output fuses (small glass ones a tad smaller than a plugtop fuse). If you have a multimeter you should be able to see if there’s any output but it may be that the unit has expired. Does it smell bad?, as the Shellac varnish gives off a distinctive smell when they give up.
LEDs, see the light.

7-8 minutes is good from those Ikea transformers