Hold the power button on the TV (not the remote) and plug the power cord back in. Release the button once the update screen appears.
: Dedicated software blogs like SoftwaresCollection often host links for various versions, including non-Bluetooth models and different RAM/ROM configurations (e.g., 1.5G/8G). tpsk706spc822 firmware link
: Frequent app crashes or "system not responding" messages. Hold the power button on the TV (not