Dimmer switch problem

This is going to sound like (another) ill-researched question.
Daughter's lounge has something like 24 small bulbs in the ceiling arranged in 2 banks of 12, each bank being fed via half of a dual dimmer switch by the door. One bulb has gone, but her husband hasn't been able to get it out from the mount so doesn't know whether it is mains or low voltage. I have always avoided these lights since early days with something that looked like this and melted the transformers above each bulb. I've looked at pictures on the net and seen that bulbs like this are called GU10, MR16, MR11 etc. Can one measure diameter or something to find out what they are?
The problem is that when they switch on in the morning in winter, the lights don't come on. If they leave the dimmer knobs turned up, first one bank will splutter into life after a few minutes, then the second. Daughter thinks this is definitely temperature related, as the lights work normally in summer.
Is this likely to be just a matter of a dually-faulty dimmer switch or is there likely to be some other possibility. Are these most likely to be mains lamps or is there a possibility of there being 12-volt transformers after the dimmers.
Thanks for any illumination!
--
Bill

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On 05/12/10 14:14, Bill wrote:

http://en.wikipedia.org/wiki/Multifaceted_reflector
Might help.
GU10 will come out with a twist and pull a la bayonet bulb and is mains.
MR16 and MR11 are usually 12V - sadly MR16 is virtually identical diameter to GU10 (around 50mm). These come out by a direct pull.
--
Tim Watts

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Tim Watts wrote:

They often have a wire circlip to undo, or a half twist type fitting. Failing that, lever the whole fitting out of the ceiling - mind the springs!!
--
Dave - The Medway Handyman
www.medwayhandyman.co.uk
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On 05/12/2010 16:03, The Medway Handyman wrote:

A rubber sucker bulb changing widget can help - stick on the face of the bulb and it allows you to pull and twist etc even if you can't get you mits on the edges.
--
Cheers,

John.

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We have two banks of ten of these miniature lights in the ceiling. With dimmers, they forever twinkle, so they are just for ornament really. Pulling out the bulbs is a bit fiddly as they don't stick out of the mountings much. A small piece of rubber tubing can help one's grip.
S
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dimmer fault is most likely
NT
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