Black screen, keeps restarting... HELP

[XboyQ]

Hello this is my first post on this forums and have searched similar posts but none of them seems helping so i posted this thread. THE problem- when I turn on my PC it makes a beep sound but doesnt show the bios screen or anything else it's just black, then after a few seconds it restarts and again makes beep sound with also black screen, this keeps going all the time except when I plug off cable... I've tried resetting bios both taking off battery and making short that cmos reset metals/wires and also im sure my UPS is working(i tried it on another PC) also I've noticed that I can open cd drive with button while my PC is on Some SPECs of my PC

Motherboard: GYGABYTE EP45T-DS3R0
Video card: ATI RADEON 38xx
Processor: Intel Core 2 DUO
UPS: Chieftec 600 W
PC is about 4 years old but it should'nt be dead, right?
And No overclocking
It worked fine yesterday...
Hope this helps
I'm open to any suggestions, please help me!!!

 

[profkefah]

check the RAM
and see if they are clean and fixed properly in their slot
also unplug your built out vga
and try the built in one
also try another monitor