This is a special situation, and you can look at the following three situations. 1): Due to the insufficient voltage of some laptops, when you connect to FOPO, one screen may not work normally. You can try to use the attached adapter to power on that screen. 2): Some new models of laptops (Like Macbook) have two TYPE-C ports, but one of the ports lacks output signal in function and leads to no working for one screen. You can try to use an additional HDMI cable to start the other monitor screen. 3): Some old models of laptops can‘t be used because they lack HDMI or Type-C port to connect with the monitor. If so, you can use a HUB or a docking station for connection or contact FOPO. And after connecting with the docking station, you need to restart the laptop and the triple portable monitor to make sure the monitor can work normally.