Screen Going Blank on Laptop

[chome4]

I'm using an old Advent 8115 laptop running Ubuntu 12.04 but using a Kde desktop, installed as 'kubuntu-desktop'. Works fine.

I've gone to settings and made sure that under 'Power', there's nothing that will make the laptop go to sleep or the screen go blank after a time period but it does!

Is there anything else I can check or do in terminal to shut down this problem of blanking my display?

Laptop specs:

uktsupport.co.uk/advent/laptop/8115.htm

[devils casper]

Does it happen randomly or after a specific time period?

[chome4]

Does it happen randomly or after a specific time period?

I've not measured the times but now you mention it, it does seem random! Also, if I'm viewing a video fullscreen, it doesn't happen. Just seems to happen if I'm viewing a vid in a small window or just leave the pc alone on a web page.

I'll take more notice of timings etc and see if there's a pattern.

The last distribution of Linux I used, Pardus, no longer supported, was default KDE and didn't do this.