Switch the cable to a different DisplayPort if the adapter has more than one port. If using a DisplayPort adapter on your computer, ensure the cable is correctly plugged into the adapter and the adapter into your computer. Use a can of compressed air to remove foreign materials from the DisplayPort on the monitor and your computer.
Also, make sure there isn’t any foreign material blocking contact between the cable, your computer, and the DisplayPort monitor. Before reconnecting the cable, ensure your PC’s DisplayPort is clean and free of dirt and dust. If your DisplayPort monitor doesn’t detect a signal from your computer, unplug the cable and plug it back in. Unplug and Reconnect the DisplayPort Cable
