Roku TV / Fire TV: black screen but sound plays

First prove it isn't input or source (press Home, change input, remove devices). Then the flashlight test: a faint image means backlight failure.

Cross-checked ~30 min moderateBrands: Roku TV, TCL, Insignia, Toshiba, Fire TV

Before you start

Unplug immediately on smoke, sparking, burning smell or a damaged cord.
Backlight/power board work is for trained techs: dangerous voltage inside.

Diagnostic steps

Unlock all 5 steps with expected values

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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.

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