The order you boot the PC and select the HDMI input it's connected to affects whether the TV and PC "handshake".
Also make sure that the PC video resolution compatible with the TV.
Sorry my phone must have deleted the text. My boyfriend just recently brought his computer tower into the living room and connected it to our tv in the living room. It's not working it did use to work before. He had just brought it from our tv in the bedroom. We have friend different HDMI cords, turning both tower and tv off but nothing is working
The order you boot the PC and select the HDMI input it's connected to affects whether the TV and PC "handshake".
Also make sure that the PC video resolution compatible with the TV.