How to do if cannot enter the Recovery mode successfully?

Solution:
In the Recovery mode, some TVs will no longer receive the signal of the remote control (bluetooth/infrared) after 3 seconds.
In order to enter the Recovery mode successfully, the following two points (distance + time interval) should be paid attention to:
① If the infrared remote control is used, the distance between the remote control and the infrared receiving window of the TV should not exceed 1 meter;
② After pressing the button of the remote control, press the power button on the TV body and the time interval between switching on the power shall not exceed 3 seconds.
If still unable to enter,  please turn off the TV firstly, then hold down the confirm key + return key of the bluetooth remote control and insert the TV power (no need to click the power button), and then let go until entering the Recovery mode.