This is most of the case with HDMI cable connections. I had a PC with NVIDIA GeForce 210 graphics card. It had a DVI, HDMI port. I connected it to a Sanyo (Panasonic) 49” Ultra HD Smart TV. I was using Windows 10 64 bit. But the signal simply refused to come in. I had the same error. But when I connected my Acer Laptop with Windows 7 32 bit, it was working perfectly. I also tried the Wireless display mode in Windows 10 but it didnt work.

Then I connected my desktop using Windows 7 64 bit OS. The HDMI handshake was successful, but the signal was hanging with bizzary time of in/out video coming in. So I felt that the graphics card also has a part in HDMI connection. My PC is a assembled one, while my laptop is a branded one.

Also there can be several reasons why HDMI AV connection may not work.