The TV turns on, displays the manufacturer's logo (Samsung, LG, Sony, TCL) for 10 seconds, then restarts. This repeats infinitely. Standard USB firmware updates fail because the TV crashes before it can read the USB drive. The Boot Extract Tool forces the TV to pause at the Uboot prompt, allowing a manual flash.
Type printenv to see boot variables. Type help for commands. To flash a new bootloader, you would use a command like:
The TV tries to start, shows the manufacturer logo, shuts off, and repeats forever. This happens when the boot partition (UBoot) or the kernel fails to hand off to the Android/WebOS system.
The TV shows absolutely no signs of life—no standby light, no backlight, no sound. The internal bootloader has been overwritten with bad data. Standard USB recovery fails because the USB ports aren't powered yet.