Prompted by the thread of led lights I got a set. I discovered when I got the panel out that I had a missing bulb..... missing because there was no power getting to it. So the panel has been unplugged a few times.
The job was done a couple of weeks ago, but lack of use of the car meant I hadn't used the car until yesterday evening. The lights work, but extinguish when the key is turned to the ignition position.
All the warning lights work as normal.
When I replaced the gauge illumination bulbs with LEDs some years ago, I discovered that the gauge lighting level could no longer be adjusted. The lighting stayed on full until the very dimmest setting, when the lights went out completely.
I reinstalled the correct incandescent bulbs and all is well.
Bulb 2721 available from BulbTown (https://www.bulbtown.com/SearchResults.asp?Search=2721) among other places.
Thanks for replying, but the problem I've got was self-inflicted. These led's, if you look at the thread that started people buying them, do respond to the dimmer.