Check the DVI cable connection from the PC to the TV 'DVI input' to ensure that it is properly secured. If the connection is good, then the problem could be due to the switching on sequence of the TV and the PC.
The recommended sequence:
Alternatively,
Press the keys on the keyboard of the PC that will toggle the PC to switch the TV to a monitor, such as 'FN' key and 'F8' together to view the information on the TV screen.