“No Signal” message LCD Monitor acer

I have read several threads about same issue, but with each thread there are different solutions, I got confused.

I have acer LCD screen connected to WinXP SP2 box, recently I experienced one of these message :

1- “ Input no supported ” .
2- “ No Signal ” and LED turns from green color to amber color.

This happened while the PC is working (i.e. not on reboot)

I thought the problem with LCD screen , I changed to other one , then same message appeared ( “ No Signal ” ).

What graphics type are you using built-in, or AGP/PCI-E/PCI

Definitely It is PCI, and since I am not near to my computer , I guess it VGA Radeon 9600

I don't think there are PCI Radeon 9600's. They're all AGP

Yes you are right, I meant to say AGP,,,please see the VGA card in the link below:
http://www.geeks.com/details.asp?InvtId=9200SE-128TV-WB&cpc=SUGG

Please see the monitor in the link below as well:
http://www.acer.com.sg/products/monitoral1717/p_monitoral1717.asp

Make sure the video connection is not loose, attach securely the screws. If not, try with a different monitor. If it works, I'm afraid your monitor is bad. If not, open your PC, remove the radeon, clean the gold contacts with an eraser (yes "erase them"), and reseat it.
If nothing works, I'm afraid it's time for a new video card.