Monitor says No Input signal Need help!

Hello,
My old graphics card I'm pretty sure died on me because it said No Input signal and when I turned on the computer The light turns on and I opened it up all the fans are running. I just took my RAM out and switched them and I haven't heard any beeping or anything The CD-ROM opens when I press the button and have tried like 5 different D-sub cables and a DVI to D-Sub adapter. I took all the cords out of my Monitor and computer and took out all the cords and cleaned them with air and then plugged in the Power cord and DVI to the monitor and computer and still nothing works. Then I took out my old graphics card and put this new graphics card in and I turned it off and placed it in my computer and then turned it on and It worked with terrible resolution and then put the CD to install the new drivers in and I turned the computer off to do some updates and put the side protector that holds all the things for my computer in so it wasn't exposed. Then I tried to turn the computer back on and was very frustrated to see the new graphics card I just bought has the same "No Input Signal" problem. Then I was thinking it was the monitor that had the problem but I tried hooking it up to my sister's monitor and that one didn't recognize input and said "Going to sleep" Finaly I took the HDMI cord and plugged that Into my TV to see if that would work and that didn't even pick up signal.


I've had this computer for about 3 years and had a GeForce 7800 GT OC
and now I upgraded to an ASUS GeForce GT 430. My computer is running on Windows 7 and my monitor and computer are both HP.


Please help I haven't had a computer for 6 days and I need to do work and school assignments.