The most common complaint we hear: "TV mein awaaz aa rahi hai, par picture nahi." If you can hear sound but the screen is black — and if you shine a torch close to the screen you can faintly see the picture — the backlight has failed. The panel and boards are working; the light behind them is not.
LED TVs use strips of small LEDs behind the panel to light the picture. They are connected in series, so when a single LED fails, the whole strip — and often the whole screen — goes dark. Some TVs first show a dim corner, a dark patch or a flickering picture before failing completely.
At City Electronics we open the TV in a clean area, remove the panel carefully, and replace the backlight strips with good quality, correctly rated strips. We also check the LED driver and, where possible, set a safe drive current so the new strips run cooler and last longer.
Common symptoms
- Sound present but the screen is black
- Faint picture visible with a torch
- Picture becomes dark a few seconds after switching on
- Dim areas, dark corners or uneven brightness
- Blue, purple or bright spots on the screen
- Flickering brightness
What causes it?
LED burnout
Backlight LEDs run warm for long hours. Over years, one LED fails open and the string stops working.
High factory brightness
Some models drive LEDs at high current, which shortens their life — especially on full brightness all day.
Lens or reflector damage
Fallen diffuser lenses cause bright spots even when LEDs work.
LED driver failure
Sometimes the strips are fine and the driver circuit on the power board is the fault.
How we fix it
- 1We test with a backlight tester to confirm the LEDs, not the driver, are faulty.
- 2The TV is opened and the panel removed with suction tools in a dust-free area.
- 3All strips in the set are replaced — replacing just one usually leads to another failure soon.
- 4Reflector sheet and diffuser lenses are inspected and fixed.
- 5After reassembly we check brightness uniformity and run a burn-in test.
Typical turnaround
Same day to 2 days
Most backlight jobs are completed the same day or the next day. For some large or rare models, strips may need to be ordered — usually within 1–3 days.
Frequently asked questions
Why replace all strips if only one LED failed?
All LEDs in the set have the same age and wear. Replacing the full set prevents another strip from failing a few weeks later and needing the TV opened again.
Is backlight repair risky for the panel?
Handled carelessly, yes — that's why we use proper tools and a clean bench. Panel safety is our priority.
How long will new backlights last?
Quality strips driven at a sensible current can last many years. We'll also share tips like avoiding maximum brightness all day.