Video signal lost

I've had my computer for a while, here are the specs:

Processor: AMD Athlon™ 64 X2 4200+ with HyperTransport and Dual Core Technology
Operating System: Microsoft® Windows® XP Home Edition with Service Pack 2
Power Supply: PC Power & Cooling 510 Express 650 Watt peak power
Motherboard: Alienware® nForce™4 SLI™ Chipset Motherboard PCI Express
Graphics Processor: Dual NVIDIA® GeForce™ 6800 GT PCI-E 256MB DDR3 with SLI
Video Optimizer: AlienAdrenaline: Video Performance Optimizer
Memory: 2GB Low-Latency Dual Channel DDR PC-3200 at 333MHz - 4 x 512MB
System Drive: High Performance - Serial ATA - 80GB Serial ATA 7,200 RPM w/8MB Cache
Primary CD ROM/DVD ROM: 16x Dual Layer DVD±R/W Drive
Sound Card: Creative Sound Blaster® Audigy® 2 ZS High Definition 7.1 Surround Firewire (IEEE® 1394)
Floppy Drive: 3.5" 1.44 MB Floppy Disk Drive - Black
Network Connection: Integrated High Performance Gigabit Ethernet
Power Protection: OPTI-UPS SS1200 Automatic Voltage Regulator 6 outlets

For some reason I will be using the computer and the video will cut out for no apparent reason, but the computer still runs fine. It will only come back on from time to time or sometimes if I restart. I was wondering if anyone might have any ideas as to why. I tried updating drivers, no help, I tried changing adapters for monitor, thought it might have gone bad, no help. I'm kind of out of ideas as to what the problem would be.

Any suggestions would be great.

 

Welcome to Major Geeks. I would say that it may be the video card cutting out, not the monitor. If you have on board video, remove the video card temporarily and use the on board and see if it still happens. This will tell you if it's the monitor or video card. Alternatively, you can try a different monitor....
Good luck!