Why my computer is not starting?

Right then, mate. Let's run through the usual suspects. Start with the blindingly obvious, just in case. Is the power point at the wall switched on? Is your power board on?

Give the power cable a firm push into the back of your computer. Check for a little black switch right next to that plug on the computer itself and make sure it’s on.

If you see any lights or hear fans, but there's no picture, it's likely a display issue. Make sure your monitor is on and its cable is snug at both ends. If there’s absolutely nothing – no lights, no sound – then your power supply might have carked it.

Hope you get it sorted. Cheers.