dimmer switch problems

[Crispy1]

4 Xenon Pro-Lite GU10 downlighters 50W 240V operating off a Doyle and Tratt 1 way touch control dimmer switch rated at 40W to 400W.

these have been fine for 3 years. suddenly the lights go off of their own accord shortly after switching on.

changed the dimmer switch for an identical one, changed the lamps. makes no difference.

now the circuit will support only 2 lamps, fitted in any of the 4 positions, but no more.

Has anyone encountered similar problems? any ideas?

 

[Ken77]

Have you checked for voltage drop?

 

[GT1]

I would isolate it from the loop and IR check the circuit as a starter. (with the dimmer removed obviously)

 

[Bright Sparks]

Can't say I have had anything similar, but working on the fact that you have eliminated the usual suspects I would check the wiring and the junctions etc, could be a breakdown in cable insulation or something more random.

 

[GT1]

Had one last week whereby a blown bulb found a poor connection right at the other end of the loop..!