Check the video resolution setting of the the video in the laptop and then check your TV manual to see what resolution the TV can handle. Some Samsung TVs for instance can accept 1080i (1920 x 1080 interlaced) but not 1080p (1920 x 1080 progressive) or not even 1080 but only 720p (1280 x 720) when using HDMI.
Sorry about the delay I have been away.
Here are some things to try.
First check that your laptop graphics adapter resolution is set to one of the following as these are the resolutions that your TV will accept when using HDMI.
Computer formats - HDMI
(Resolution - refresh rate)
640 x 480 - 60 Hz
800 x 600 - 60 Hz
1024 x 768 - 60 Hz
1280 x 1024 - 60 Hz
1360 x 768 - 60 Hz
1600 x 1200 - 60 Hz
1920 x 1080 - 60 Hz
If one of the above is selected and there is still no picture then try the following:
Press the Home button on the remote the select Setup > TV Settings > Picture > OK then find and select PC Mode then OK
You may have to press the Adjust button on the remote and select Picture Format > OK then Unscaled for the best picture.
If still no good this advice is from the User guide:
If the TV does not recognize the HDMI device and no picture is displayed, switch the source from one device to another and back again.
By this I assume it means that if you can, connect your laptop to one HDMI input and connect another HDMI device e.g. your Chromecast to the other HDMI input, (I think you have 2 HDMI inputs - is this correct?) then point the TV source input to the laptop, if no signal select the Chromecast input, get a picture and then switch back to the laptop and see if the laptop picture is now there.