If you are still not receiving a signal even after replacing your video card, you may also need to replace the computer's power supply and, in a worst-case scenario, your computer's motherboard.

Loose or disconnected cables: A loose or disconnected cable between the monitor and computer can cause the monitor to display “no signal.” Faulty cable: A damaged or defective cable can also ...

The standard wire for connecting PC peripherals is also used for game-console controllers. ... This optical cable transmits a purely digital audio signal from components and computers to receivers.