1. You need to connect the USB port marked "5V+Touch" to the Raspberry Pi to activate the touch function.
2. The screen will go into self-testing mode(color cycling) when detecting no signal input, please double check the HDMI cable and make sure they are connected correctly.
The self-testing mode can not be turned off permanently, you can turn off the screen when your PC is in standby mode.
3. When connecting with the converter connectors, the brightness should be under 75% and the volume under 50%, or the screen will go black due to insufficient power supply, please connect to an external power cable to fix the problem.