My computer screen turns off by itself

[crokojot]

NIce...and how did you fix it? I got HPLA2405wg , and sometimes in PR when i press esc , monitor goes to sleep mode, i can hear sound ...but i must restart my PC to make it work again...i got no power schemes on ...so ....s.o.s

System specs:
-Processor:TripleCore AMD Athlon II X3 450, 3200 MHz (16 x 200)
-RAM Memory: 4 GB
-SO: Windows XP
-Video Card: ATI 6850
-Monitor: HP LA2405wg