Ok, first off, I am not sure where to put this thread, so I will post it here, hope it is OK.

Now the problem:

My brother-in-law and I built a computer. Everything seems to run fine, however, when I am playing a game, the monitor goes into sleep mode and can not be woken up (The monitor light turns to orange).

Now, I am pretty sure nothing is overheating. Playing Medieval Total War (I know it's a bit older but...) the temp on the graphics card, CPU and mother board never gets above 50C (about 48C). I also took off the side of the case and aimed a house fan at the mother board. All temps went down 10C and the monitor still went into sleep mode.

I have also adjusted the power setting to never turn anything off.

I have already tried another already working monitor and the same thing happened.

Is there something in the BIOS that could be causing this? Is there any sites that give detailed explanations of BIOS settings?

What the heck is going on? It is very frustrating.

Here are my specs:
AMD Athlon 64 3400+ 2.4Ghz
1 MSI Geforce NX6600GT PCI express 128mb
Asus K8N4-E Deluxe Mother Board
1 Gig of Ram
1 Seagate 200Gig Hard Drive
Thermaltake Silent Boost K8 fan/heatsink
Antec Smart Power 400W
1 DVD RW Drive and 1 Floppy

How do you get it back on? resetting the computer?
That is definatly not a monitor problem. The fact that you tested another monitor and got the same result is proof enough for that. If it happens after a bit of gaming my first guess would be a heat problem somewhere. The monitor is going to sleep because there isn't any signal going to it anymore, ie the comp stopped working.
Do you have anything overclocked? What about the ram temps for both system and video card? Are all your drivers fully updated?

<A HREF="http://www.folken.net/myrig.htm" target="_new">My precious...</A>

Yeah, to get the monitor back on I have to power down via the power button on the tower (the keyboard and mouse seem to stop working)

The temperature for my graphics card playing medieval total war was around 48-50C. The threshold for my card says it can go up to 145C. The motherboard was about 38C and my CPU about 48C. As far as temp for video card and system ram, I am not sure, I do not know where to get that reading.

I also haven't overclocked anything.

No my drivers aren't updated, because I won't have access to the internet with the new computer for about two weeks (I go back to College). I have no modem in the new computer.

I just noticed my graphics card (MSI Geforce NX6600GT PCIex TD128E 128MB) has no power connector, to allow power directly from the Power Supply. So I called the card manufacturer and they said the card didn't need one, it would get enough power from the motherboard itself? What do you think? Because another fellow seemed to have the exact same problem as me and fixed it by connecting the card to the power supply (he forgot to).

Grrr.....

I'm having the same problem, i've had the system as is for 2 years. It just started doing this so i updated the driver for the graphics card (nvidia quadro4 980xgl) and it still does it. It does it when ithe system first boots it will do it when i click on a file, it usually happens when an action is performed.

The only thing new ive done is load Splinter Cell Pandora Tomorrow. Could that be it???

How old are your bios? Try updating it. See if you have any fault bios setting. Do you have a good power supply?

Ok, i went through every possible update nothing chancged then i checked, the info on the monitors controll panel i.e. its model and serial info and it was all garbled with error codes so i called nec/mitsubishi they said "yeah it's gone bad, we can fix it, bring it down". Luckily i live in hollywood and the repair warehouse is in Compton i drove it down, they switched out the boards and !voila! no more problems. Wow!!! i thought my video card was going to hell good this it wasnt that thing wasnt cheap (nvidia quadro). Thanks for your help. O and to the other guy with the same problem have you tried another monitor?? good luck

update bios,update vga driver, format hard drive, low level format..., update monitor driver, changed vga card, changed monitor,changed hard drive, changed memory, changed DVD ROM + DVD RW even changed keyboard and mouse.......
the problem was the PSU. Just needed more power
:-) hope it helps most of you