LED backlight strip replacement (direct-lit LCD TVs)

On direct-lit sets the strips sit behind the LCD and optical sheets. The job is mostly careful handling: lift the panel by its frame, keep the sheets in order, replace the whole strip set by part number and test before closing.

Cross-checked ~120 min advancedBrands: All

Before you start

Power-supply boards and backlight drivers hold dangerous voltage and can stay charged after the set is unplugged. Internal work is for trained technicians only: unplug, wait several minutes, and never touch the primary side of the power board, the large filter capacitor or the LED output connector with the set connected.
Never power the strips from the TV's driver while handling them; driver output is high-voltage DC.
Handle the LCD glass by its frame only; do not bend its flex cables.

Diagnostic steps

Unlock all 5 steps with expected values

Full library + AI assistant for $34.90, one time.

Get lifetime access

OnCall Tech is a reference tool for trained technicians and can make mistakes. Always disconnect power and confirm with the manufacturer's documentation before you work.

More tvs guides

Component test · TV

TV LED backlight strips and LED driver

LED strips are wired in series strings and run from a constant-current driver at high DC voltage (often around 80-200 V total). One dead LED opens the string and the driver shuts down. Test LEDs with a backlight tester, not a meter diode range, and replace all strips as a set.

6 steps ~120 minadvanced

Component test · TV

T-con (timing control) board: board or panel?

The T-con converts video from the main board into the signals that drive the panel rows and columns. Loose ribbons, a blown T-con fuse or a failed T-con cause image faults; lines that stay fixed in the same place usually mean the panel itself.

5 steps ~45 minadvanced

Component test · TV

TV power supply board

The power supply board makes a standby voltage that is always on, then switches on the main rails when the main board sends a power-on signal. Check standby, then the power-on signal, then main rails. The primary side holds a high-voltage charge.

5 steps ~45 minadvanced