Dear Samsung users, according to your description, we suggest you: 1. When the laptop is connected to the TV, the TV needs to switch to HDMI mode, and the laptop needs to press FN+F4 to switch. 2. If the notebook press FN+F4 and there is no response, there may be something wrong with your notebook shortcut key software. You can refer to the following solutions: 1. Please uninstall and reinstall the shortcut driver easy dispiay manger software of the corresponding system, and then try to adjust. 2. Please open the device manager to check whether the video card driver is normal. Try to uninstall and reinstall the graphics card driver of the "corresponding system" through the above link. 3. Try to restore or reinstall the operating system (please back up important data in advance before selecting this option). 4. If it still can't be solved, I suggest you go to the repair center designated by Samsung for testing. Samsung knows that it will provide you with high-quality solutions and answer your questions attentively, hoping to get your satisfactory evaluation.