Chromecast not controlling TV via CEC
Quote :CEC, or Consumer Electronics Control, allows for HDMI devices to be controlled with one remote control. If your television has CEC support, you may be able to turn on and change the input on your TV using your phone, tablet or computer while using Chromecast. Please note that in order for CEC to work (if CEC is supported by your TV), your Chromecast must be powered by a power outlet.
Manufacturers often call CEC by different names, including Anynet+ (Samsung), Aquos Link (Sharp), BRAVIA Link and BRAVIA Sync (Sony), HDMI-CEC (Hitachi), CE-Link and Regza Link (Toshiba), SimpLink (LG), HDAVI Control, EZ-Sync, VIERA Link (Panasonic), EasyLink (Philips), and NetCommand for HDMI (Mitsubishi).