monitor turns out black after opening a game

[waaaks!]

I'm having issues with my monitor this past week, it seems like my monitor turns out black after opening a game (gta san andreas, counter strike 1.6), to fix it, I need to turn off the monitor, and turn it back again after some seconds.

I don't have this problem in the past months, I need to find the thing that causes this (monitor? video card? ram?).

I'm running nvidia ge force 5500 256mb video card, 1g ram, 3.0 ghz, pentium IV.

 

[Tru_Power22]

Sounds like a problem with your monitor. Try using a different and test to see if the problem occurs.

 

[waaaks!]

now things are messed up, I opend my CPU, and tried to replug my video card, now my monitor doesn't show, I removed my video card and used the default video card of the CPU (32 mb), now, it does load normaly, so this means, its the video card fault.