Double Dimmer switch (one side dead?)

[arthur071169]

Yesterday I thought the bulb went on one of two seperate lights controlled independentally through a double switch dimmer.
2 lights in the living room, single plate, 2 switch dimmer!

After changing the bulb, still dead, so I put the second, working bulb in, dead!
put it back and it worked in its original light fitting.
I turned off the dimmers at the switch and metered the current going through the suspect light.
With the dimmer in the off position there is about 23 volts going through to the terminals in the ceiling rose fitting.
With the suspect dimmer only 'just' switched on, there is a full 240 volts getting to the fitting.
Still no light though (perhaps no current, just voltage).
What the heck is going on, I thought with the switch in the off position there should be ZERO volts to the ceiling rose...

I do no tkno wthe age of the dimmer switch, but I only just bought the house and there are some old original features (house about 30 years old)

 

[plugwash]

did you have a working bulb in when you took those voltage measurements,

knowing voltage is pretty meaningless without knowing impedence.

i suspect the dimmer is blown though,

 

[ban-all-sheds]

Swap the outgoing conductors in the dimmer. If the fault moves, then the dimmer is to blame.

If it doesn't then the fault lies somewhere after the dimmer.