Screen went blank

Let's cover the obvious.

The TV works fine with other inputs (cable TV), right?

The laptop is plugged into the VGA port on the TV and the input setting is set to "VGA", right? (or does toy computer have an HDMI port that you are using?)

Is it a laptop or a PC?

If it's a laptop and the TV is connected correctly and functioning otherwise, you need to turn on the remote display port of your laptop. It's a key sequence that toggles from laptop -> external -> both.

If it's a PC, it might be a signal incompatibility. Try different resolutions or refresh rates.

Good luck.