Computer and Monitor problems

Hi, I had this computer for over a year now and everything was working fine until i got this new monitor by DELL the W1700 HDTV monitor. When i plugged in the monitor and started my computer, the computer did not start up with the monitor and I didn't even hear the windows xp sound go off in the start up. So, I manually turned off the computer and unplugged the monitor cables and replugged them and started it up again, but still did not work. Then I plugged in my old monitor and now even my old monitor does not work either. I dont know much about computers. I do not know what wrong with my computer because its been working fine for a year now. Please help.

Sometimes we overlook the obvious: see if you accidentally flipped the PSU power switch off (on the back of the computer) while you were plugging things in. If you heard fans start up though, that's not it. Possibly you unseated the video card when you changed the cables. Might have to open up the case and make sure all is snug. This would also possibly cause windows not to boot up, if it detected a hardware problem on the video card... etc.

checked it, but some of my friends tell me that I might have to replace the video card. Like when i turn on my computer I don't hear that beep sound that i should hear when the computer sounds... I am thinking its either the mobo, CPU, or video card but do not which one I have to replace.

hey mate......

have u tried..... using another monitor that u know wrks on the computer.. may b the monitor doesnt wrk? or it mite not have enough power to wrk? does it have its own power suply eg conected to the wall?
it mite not be compadable with ur vidio card..
i reakon u should try another monitor that wrks. or try that monitor from dell on another computer and c if its the monitor..

hope that helped.
l8ers