LED & Appliance Repair

What to Measure in LED and Appliance Repair

Before you open a lamp fitting or a domestic appliance, a short sequence of checks tells you where the fault really lives. Run these measurements in order and the repair usually narrows down to one component.

• Check the live-neutral polarity at the light fitting before reconnecting
• Verify the supply voltage at the appliance inlet is actually present
• Trace a lamp that stays dark by testing the switch in both positions
• Measure AC voltage across the LED driver output terminals under load
• Check continuity on a dead 230V outlet before suspecting the appliance
• Confirm the earth path back to the panel on metal-bodied appliances
• Detect intermittent drop-outs by watching the display during a continuity test

How to Check Voltage and Continuity

A multimeter, used methodically, turns most lamp and appliance faults into a short checklist. Work the same routine every time so no step gets skipped.

1. Test the meter first. Plug the leads into the correct sockets, set the rotary switch to AC voltage mode, and confirm a known-good outlet reads mains voltage.
2. De-energise the circuit where you can and prove it is dead. Set continuity mode and touch the probes together to confirm the buzzer sounds before tracing anything.
3. Check the supply at the lamp or appliance. In AC voltage mode measure live to neutral and live to earth, and watch for the reading to sag when the load is switched on.
4. Isolate the suspect part with the power off: test the switch contacts, fuse and LED driver input in continuity mode.
5. Safely re-energise the circuit, then check the LED driver DC output across its output terminals while the lamp is connected, keeping the capacitor-discharge caution in mind.
6. Re-verify after the repair: confirm live-neutral polarity at the fitting and that the supply voltage holds before you close the unit back up.