: Do not turn off the power during the update. The TV will typically reboot automatically once finished. Troubleshooting and Technical Resources
Release the button once the standby light starts blinking or an "Upgrading" screen appears. tpdnt72563pb782 firmware best
If firmware does not solve the issue, the problem may be hardware-related. tcl 43d1240 chassis tpd.nt72563.pb782 sm - Elektrotanya : Do not turn off the power during the update