touch dimmer switch stops working after a few days - any idea why?

Hi All The recent thread about blowing bulbs reminded me of this:
Some years ago I fitted a pair of touch dimmer switches from TLC:
http://www.tlc-direct.co.uk/Products/VLIDQ1401MS.html
These are for for ceiling lamps in our living room. These were originally 'standard' light bulb fitting; I have since replaced them with two fittings each with 3x Halogen g9 40W bulbs.
Cut to a number of years later, and over a period of a year or som, both dimmers got less reliable (light would cut out on its own etc.). Eventually I replaced them both with the same item.
One of these works fine. The second dimmer seemed to fail after a week or so (light failed to turn on when touch place pressed) and I returned it to TLC for a replacement.
However there seems to be more to it than that; What seems to happen is that after a few days the replacement dimmer also stops working. If I then trip the mains MCB for that lighting circuit, and re power it, it is fine ... for a few days.
The wiring to the dimmer is solid and I don't think anything else has been changed in the lighting circuit.
Assuming I've not just been unlucky with dwo dodgy dimmers, any thoughts as to what might be causing this? I originally wondered if the load might be too little but the switches are rated at 60W minimum...
Thanks a lot J^n
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jkn wrote:

'standard' light bulb fitting; I have since replaced them with two fittings each with 3x Halogen g9 40W bulbs.

dimmers got less reliable (light would cut out on its own etc.). Eventually I replaced them both with the same item.

(light failed to turn on when touch place pressed) and I returned it to TLC for a replacement.

after a few days the replacement dimmer also stops working. If I then trip the mains MCB for that lighting circuit, and re power it, it is fine ... for a few days.

what might be causing this? I originally wondered if the load might be too little but the switches are rated at 60W minimum...

Is the earth connected all the way through to the back box and to the dimmer itself?
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On Thursday, May 16, 2013 1:00:35 PM UTC+1, jkn wrote:

'standard' light bulb fitting; I have since replaced them with two fitting s each with 3x Halogen g9 40W bulbs.

dimmers got less reliable (light would cut out on its own etc.). Eventually I replaced them both with the same item.

so (light failed to turn on when touch place pressed) and I returned it to TLC for a replacement.

hat after a few days the replacement dimmer also stops working. If I then t rip the mains MCB for that lighting circuit, and re power it, it is fine .. . for a few days.

n changed in the lighting circuit.

as to what might be causing this? I originally wondered if the load might b e too little but the switches are rated at 60W minimum...
I'm not sure how this minimim works, but I have noticed that if my dimmer ( rotate to dim, push for on/off) is set to mininmum and I push for ON the li ghts don't come ON, even on turning it 'up' but if I switch push off/on aga in then they light and I can then dim them to miniumum without a problem.
I assume they still use SCRs so maybe they need a certain current flowing t hrough thier gates in order for them to conduct properly, if not they stay off. The current needed might equate to a 60W of load.
Remebring that they don;t reduce the current to the load but switch off or on depending what part of teh sine wave cycle ...
I don;t have an MCB's just fuses so not sure about that side of it.
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On 16/05/2013 13:00, jkn wrote:

I don't have an answer for you, but do recall someone describing exactly this situation with their lounge lights on the same dimmer to me as well. So I guess its a known issue. I would be tempted to call varilight and ask for their tech support people.
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Cheers,

John.
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Hi John

Hmm ...
http://www.varilight.co.uk/technical/t17.html
""" VARILIGHT® Technical Support VARILIGHT Touch or Remote Control Dimmers
My Touch or Remote Control Dimmer won't turn on
This problem can sometimes be solved by resetting the dimmer by turning off and on again at the circuit breaker. """
not impressed ... I'd better give them a call.
Thanks J^n
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On Thursday, May 16, 2013 3:37:38 PM UTC+1, jkn wrote:

y

t

ff and on again at the circuit breaker.

Yeah tech support.., <IT Crowd> have you tried turning it off and on again :-)
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This rememinded me of a guy whos mobile kept turning on his hall light which had a touch plate switch on it. Not terribly useful... Brian
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Well most touch devices like this have a high impedance impute that either picks up noise from the person touching it, or it just changes an oscillator. Not up to speed with the latest methods, but if the plate picks up stuff, one can imagine the situation where it will no longer respond to touch as its already saturated or overloaded. I've never had much luck with these touch dimmers myself and though I do not now have much need of them, I thought by now they would have got them working reliably!
Brian
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Hi guys, from the website your shared, this kind of dimmer switch is too old one, we always use glass panel dimmer switch. it's more safety then that one
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