HP PC shuts itself down after about 5 minutes

[popegregory]

No warning, it just shuts down. The blue power light stays on but the screen goes blank and informs me that there is no input signal detected.

If I start it up in safe mode and then restart, it seems to be ok.

Any ideas?

[popegregory]

Silly question but do I just give it a Hoover and make sure it's not clogged up with dust?

[popegregory]

Thanks all, I'll give that a go in the morning.