My Screen Goes Black HELP!! Immediatly!

ok i have a ati radeon hd 2400 agp

when i play soildier front my screen goes black i have a lg 22 inch and when my screen go black it says analog and power save im like wtf!

my dad said he gona get a pci no express just pci whats the best pci i can get for a

compaq presario sr1214nx

amd athlon xp 2900+ 2.00 ghz 1.50 gb of ram i dont lagg in the game or anything

also tell me why my screen black out i can still hear game and stuff and some time it freezes to.
tell me if u need more specs

whats the best pci

and my dad said he might change the whole mother board out so whats a good mother board? for compaq presario

whats best mother board for compaq presario intell 4 dont know help help help

jjftw when the monitor goes blank does the monitor light stay green or those it go to yellow.

also does any other game make the display go blank ?

also you didn't mess with the power scheme in windows program did you! settting this to use less power will cause problems.

don't know what kind of games your playing other than Soldier front.