PC won't start!

[tracymort]

It's recently taken increasingly long times to start. Yesterday it took 40 minutes after pressing the power button!
Today, nothing, zilch. All i get is on lights lit up and the fan goes round. Blanks screen, monitor says it's getting no signal.
I checked everything is plugged in but after that I'm pretty much clueless what to do!

[OBonio]

Almost definitely a hardware problem.

What make is it? Is it under warranty? Is there any beeping when you turn it on? If so, how many beeps and how long?