Unlike OLED, an LED/LCD TV doesn't generate its own light per pixel — the liquid crystal layer only filters colour and contrast, while a separate backlight (strips along the edges, or a full array behind the panel on Mini-LED sets) provides the actual illumination. When the backlight fails, the picture can vanish entirely while the TV otherwise behaves normally — sound plays, the smart menu still works, but the screen stays dark.
Backlight strips are LED chains: when one LED in a series fails, it can take out the whole strip or zone, which is why backlight faults often show as a dark band or half-screen rather than total darkness. The driver board that supplies the backlight's voltage is a common secondary point of failure.
A classic diagnostic trick still applies: shine a torch at an angle across a "black" screen. If you can faintly make out a dim image, the panel and processing are fine — it is the backlight that has failed, and that is usually a very repairable fault.
Brands we fit and service
The led backlight market splits into hardware built for South African conditions and lookalikes that fail at the first hard season. These are the manufacturers we trust on our installations:
- Samsung
- LG
- Sony
- Hisense
- TCL
See our brand guides for how these manufacturers compare.
When the led backlight goes wrong
These are the failures we're called to most often — each with its symptoms, causes and our fix on the dedicated problems page:
- Screen is black but sound still works — No picture at all, but the TV powers on, the menu sounds play, and streaming apps make sound as normal.
- Screen is dim or dark in patches — Parts of the screen are noticeably darker than others, or the whole picture looks washed out and dim.
- Screen flickers or pulses — The picture flickers, pulses, or briefly blacks out and recovers, especially noticeable on darker scenes.
- Screen has a coloured tint or uneven glow — A pink, green or yellow tint across part or all of the screen, or visible bright/dark zones ("clouding").
Need this fixed or installed?
Our TV Backlight Repair service covers led backlight work — quoted upfront and backed by our 12-month workmanship warranty.