Screen repeatedly shuts down

[gizzmo66]

Hello people

Wondered if any one could provide solution to my desktop shutting the screen down after 2 or 3 seconds. When i start up system i can observe all usual stuff and once desktop starts to settle screen will shut down, if i repeatedly turn off and on everything is running, but screen continues to go blank after 2 -3 secs.

monitor settings are all set to never, i have tried hitting F8 when starting but cant locate safe mode.

Any ideas?
Cheers

 

[Igorian]

Have you tried a 2nd monitor to eliminate it?

Do you get the startup menu when you hit F8?