If the TV screen shows the start-up screen of the set-top box, and then prompts "No signal", this phenomenon proves that the audio and video cable (red, yellow and white) connection between your set-top box and the TV is basically fine, but the TV RF input signal cable (note: not three red, yellow and white) is not connected to the RF input port of the set-top box, or the TV RF input signal cable is not connected to the junction box on the wall, or there are other disconnected places in your room.

Check the line connection.

Check whether the TV RF input signal line is connected to the RF input port of the set-top box, or whether the TV RF input signal line is connected to the junction box on the wall, or whether there are other open circuits in your room.

Adjust channel settings

If there is no boot screen of the set-top box on the TV screen, and then there is only a blue screen without any text prompts, then there is something wrong with your TV channel settings. Please press the source key or AV/TV key with the TV remote control to switch the TV from analog TV channel to video channel.

Ask professional maintenance personnel for help.

If the above methods still can't be solved, you must call the local cable TV customer service number and ask professional maintenance personnel for help. Hint, there is no need to search the channel again.