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Troubleshooting Common Light Switch and Lighting Problems

6 min read · 8 Oct 2025

Lighting problems split cleanly into two categories — the lamp, and everything around it. Half the calls we attend turn out to be the lamp itself.

Six common faults and the test that confirms each

  • Flickering — usually dimmer-LED incompatibility, or a loose neutral; swap the lamp for a non-dimmer LED to confirm
  • No power, switch clicks — bulb at end of life, or a failed driver in an LED fitting; lamp swap confirms
  • No power, switch silent — broken switch contact or loose terminal at the switch; verify with a continuity check
  • Half-bright — neutral fault or a stuck dimmer; check at the lamp and at the switch
  • Switch face warm — loose terminal behind the switch; isolate and inspect
  • Buzzing from a dimmer — wrong dimmer-lamp pairing; specify a trailing-edge dimmer rated for LED

Why "swap the bulb first" is real advice

A modern LED fitting has a driver inside the lamp head, not at the ceiling. Driver failures present exactly like wiring faults — flicker, no light, intermittent. Try a known-good bulb in the same fitting before opening accessories. It is the fastest test on the list.

When to stop and call

  • Burning smell at the switch or fitting
  • Brown or yellow heat marks on the switch face
  • Persistent flicker that survives bulb swap and dimmer removal
  • Multiple lights on the same circuit all behaving strangely
  • Any visible spark when the switch is toggled

A spare bulb is the cheapest test instrument

Keep one known-good LED bulb of each common base type in the home. Swapping it into a misbehaving fitting takes thirty seconds and confirms or eliminates the simplest cause before the electrician is called.

Read next

Why Singapore uses BS 1363 13 A sockets, the four faults that account for most "socket stopped working" calls, and the right way to specify a replacement.

Electrical Sockets in Singapore: Standards and Common Faults

Previous: How Light Switches Work — and How to Choose Them

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