Why does the portable monitor not display when connected to a mobile phone.

Why is the screen not displayed when the V2com P4 is connected to a mobile phone.

This is due to the fact that the screen requires power that the mobile phone cannot support. the P4's screen can only max out at 58 when connected directly to a mobile phone without an external power supply.

When the screen goes out. How to change the brightness.
A:You can connect the type c connector mobile phone charger to TYPE C 1/2. to provide an extra power source.

At this time, the screen shows. Then press and hold the scroll button at the back of the screen.

Adjust it to 50. your mobile phone can then be used without additional power.

At any time by connecting the power supply. to provide an additional power source for the screen. Reduce your phone's power consumption.