A dead flat-screen is not always dead. Work through these checks before writing off the set.
Modern televisions fail in a small number of predictable ways, and the symptom tells you a great deal about which one you are dealing with.
No light at all
If the standby LED is dark and nothing responds, start with the obvious: a different outlet, a different power cable if it is detachable, and a power cycle — unplug for sixty seconds while holding the power button on the set to drain residual charge. If the LED stays dark, the power supply board is the prime suspect.
Standby light on, but no picture
- Shine a flashlight at an angle on the screen with the TV "on" — if you can faintly see a menu, the panel and mainboard work and the backlight has failed.
- Listen for the start-up click or sound; audio without picture also points at the backlight.
- Try each input and a different HDMI cable to rule out a source problem.
- Check that the set is not in a store demo or auto-off mode.
Clicking on and off in a loop
A repeated click with no picture usually means the power supply is trying to start and shutting down on a fault. That is normally failed capacitors on the power board or a shorted backlight string.
“The flashlight test takes ten seconds and tells you whether you are dealing with a backlight or a mainboard.”
Worth repairing?
Backlight and power board repairs are usually economical on larger, more recent sets. A cracked or lined panel is not — the panel is most of the value of the television.