What does a driver failure look like?
The whole module goes dark, flickers or runs at the wrong brightness while the LEDs themselves are usually fine — the fault is in the electronics that feed them.
A driver failure is a fault in the LED driver, the electronics that sit between the isolation transformer and the LED module and regulate the current the LEDs receive. Because one driver feeds the whole module, it tends to hit all of the module at once: fully dark, flickering or flashing, or the wrong brightness, including output that does not follow the circuit’s brightness steps.
The LEDs themselves are usually intact, so the driver is checked and replaced as a unit before the module is condemned. Heat, surge, moisture and ageing are the usual causes. The isolation transformer separates the fixture from the series loop, so a driver fault normally stays local to that one fixture. A suspected failure is isolated, locked out and proved dead before the fixture is opened.
- Read the symptom. Whole module dark, flicker or flash across every LED, or dim and off-step.
- Check the pattern. One fixture points at the fixture side; several fixtures or a whole circuit points at the loop, the CCR or the cabling.
- Isolate. CCR off, locked out and tagged; prove the circuit dead.
- Look first. Check the seal and housing, the pit for water, heat marks or discolouration on the driver, loose connectors and thermal contact.
- Prove the supply. With the circuit isolated, check the transformer secondary and the connections feeding the driver before blaming it. Any live test is made only as the manufacturer and site procedure specify.
- Replace and re-test. Replace the driver as a unit, check output at each brightness step and for flicker, inspect the module, and record the findings.
Whole module dark, flicker across every LED, or wrong brightness that ignores the steps. The module is usually intact.
Part of the module dark, an uneven beam, or output and colour that slowly drift. See LED failure.
Frequently Asked Questions
Q1What is a driver failure in airfield lighting?
A fault in the LED driver, the electronics between the isolation transformer and the LED module that regulate the current the LEDs receive. It shows as the whole module dark, flickering or flashing, or running at the wrong brightness, usually with the LEDs themselves undamaged.
Q2How does a driver failure look different from an LED failure?
By the pattern. A driver feeds the whole module, so a driver fault tends to affect all of it at once: fully dark, flicker across every LED, or brightness that is wrong or ignores the brightness steps. An LED fault more often leaves part of the module dark, an uneven beam, or output that fades slowly.
Q3Does a failed driver mean the LEDs are damaged?
Not necessarily. A driver can fail on its own and leave the module intact, which is why the driver is checked and replaced as a unit before the module is condemned. A driver that fails by passing too much current can damage the LEDs as well, so both are inspected.
Q4Can a failed driver affect the rest of the series circuit?
Normally it stays local. The isolation transformer separates the fixture from the series loop, so a driver fault usually darkens or disturbs only that fixture. If several fixtures or a whole circuit are affected, the cause is more likely in the loop, the CCR or the cabling, and the circuit is investigated as a circuit fault.
Q5What causes drivers to fail?
Overheating and the ageing of components that heat shortens, lightning or switching surges, moisture reaching the electronics, a poor or open connection on the input or output side, and mechanical damage. Heat and moisture are the common ones, so seals, potting and thermal contact are checked early.
Q6Is it safe to open a fixture with a driver fault?
Only after the circuit is isolated, locked out and proved dead. Series circuits carry high current, and a fixture can hold voltage where it should not. Follow the site's permit-to-work and the manufacturer's instructions.
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