If your display shows no picture with the Satechi Core USB-C to 4K HDMI Adapter, check these in order:

1. Make sure your monitor, TV, or projector is set to the HDMI input you plugged into.
2. Check that your HDMI cable works. Try a different HDMI cable if you have one.
3. Make sure the USB-C port on your computer or tablet supports DisplayPort Alternate Mode (DP Alt Mode) over USB-C. The adapter needs this to send video.
4. On a MacBook Neo, use the USB-C (USB 3) port closer to the hinge. The other port does not support video.
5. Check the white light-emitting diode (LED) on the adapter. It lights up solid white when the adapter is connected and receiving power.