GU10 / E27 LED: flicker, buzzing, ghosting

Use this decision path (same logic as our French interactive tree). If the fault involves the consumer unit or burning smell, stop and call a registered electrician.

1 — Main symptom

Flicker when on, especially at low dimmer setting → check dimmable marking, trailing vs leading edge, minimum load, replace incompatible dimmer.
Buzz from dimmer or lamp → halogen-era dimmer on LED, under-minimum load, mix of dimmable and non-dimmable — use LED-rated dimmer and matched bulbs.
Glow or flash when “off” → standby current through smart/no-neutral switch or dimmer leakage — bypass, compatible dimmable LED, or smart bulb with switch locked ON.
Flicker at 100 % on a simple switch → loose lamp, failing driver, or bad contact in GU10 holder — try another bulb, check lampholder.

Typical fixes (from our tree leaves)

Case	Difficulty	Time	Cost
Non-dimmable LED on dimmer → swap for dimmable or remove dimmer	1	5–15 min	£5–25
Leading-edge dimmer + dimmable LED → trailing-edge LED dimmer	2–3	20–45 min	£25–55
Single low-power LED below dimmer minimum → add load or “low load” dimmer	2–3	25–50 min	£10–50
Smart switch without neutral + ghosting → manufacturer bypass at rose	3–4	30–90 min	£4–15 parts (+ electrician)

Matrix: dimmer × LED (FR). Smart bulbs: troubleshooting hub.

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