LED GU10 lamp flickers and goes out in one socket but not another

Does the switch have any kind of dimmer or 'smart' functionality, or is it a simple on/off switch?

Theo

One possibility is that the MiniSun lamps have slightly different pins/connections compared with other brands and these just happen to make imperfect connection when used in that particular socket.

Difficult to test really, maybe some contact cleaner squirted into the socket will sort it out.

It's a simple single-pole switch. Well, two of them side by side in a single plate, with the other switch controlling another lighting circuit for the other side of the kitchen, and that circuit *does* have Philips Hue lamps.

No, but I can think. I too have had many issues with lamps flickering: I have dimmers meant for incandescents and the success with 'dimmable' bulbs varies from non linear, to flickering, to nothing at all.

Worse, in this room there are three sets of dimmable lights: and issues on one set cause flickering on another circuit.

Gradual replacement with 'smart' dimmable LEDS is reducing the issues. My take on this is simply 'RF'

Cheap chinesium LEDS with any but the most basic electronics are probably reacting with the mains wiring, which is inductive and capacitative enough at MegaHertz frequencies to make a huge difference to stability. They oscillate, dim, go out, stop oscillating etc etc.

Dimming makes this worse and cross coupling between circuits makes them interact

So you might try mains suppression capacitors across the mains or a common mode choke in it...

But honestly. Use these bulbs where they work and get better ones for the problematic circuit.

Ah. The Chinesium Curse ;-)

I did have problems when we first moved to this house with another brand of GU10 LED lamps. I noticed that some TV recordings from Freeview were failing with an abnormally large number of transport errors. It took me a while to spot the common factor: BBC1 or BBC2, and only later in the evening.

What happens later in the evening? Ah! Lights. I discovered that it only happened when the lights were on in my study which is directly under the TV aerial that is mounted on the gable end. Why was it only affecting some channels?

By removing lamps in turn, I came to the conclusion that one of the lamps (they were various manufacturers) was chucking out RF interference at about 482 MHz, the PSB1 multiplex frequency for Belmont. Another lamp of the same make did the same. One of a different make was fine.

So I labelled those lamps "Not to be used in the study" and they've been used in other locations around the house, further from the aerial, without any problem.

Indeed, but this is in all probability not SMPS. It is akin to why we used to put the odd micro-henry in the output of an audio amplifier, and a resistor and small capacitor across it. Some values of speaker+speaker cable encouraged a parasitic oscillation that burned out the amp,. This was not in the audi range but 0 depending on the bandwidth of the output transistors - in the kHz to MHz range.

It is te sane reason why we put - say 470 ohms in series with a power MOSFET gate whose actual impedance is tens of Megohms. The gate resistance is very high ,but the capacitance is not. And a first order roll off of MHz frequencies is handy.

Cheap and cheerful manufacturers remove components until a good design stops working...and add only the last one back.

It is cheaper to replace or refund the ones that don't work than to make them all work.

Mechanical tolerance of the pin contacts on the bulb coupled with the tiny bit of metal in the holder that acts as spring contact and previously has been stretched slightly by a bulb with pins on the larger size of the tolerance.

Not GU10s but I've had problems in the past with screw in ES bulbs where the centre connection on the base of the bulb hasn't protruded far enough to make firm contact with its mating in the holder.