I have Win XP Pro running on a P5QPL-AM mobo. I bought a Radeon 6570 not knowing it needed a minimum of a 400 PSU.
I bought and installed a Cooler Master Extreme Power Plus 500w PSU
I disabled the on board video and installed the software for, as well as the Radeon card.
On boot up I get one beep from the bios but the monitor stays blank with the light flashing as inactive. Windows doesn't open the new hardware wizard yet I get a yellow "?" at Mutimedia Controller.
Any help appreciated.
I am severly confused by your post. So first lets try to clearify some things:
1: Is the 6570 supported by your board
2: Did you unistall the drivers for the on board video card before disabling it?
3: How did you disable the onboard video?
4: did you install the Drivers for the new 6750 before installing the Card?
Now for posting. Check your motherboard manual for clearification, but 1 beep usually means POST passed with no errors. I don't want to sound insulting, but you did make sure to switch the Monitor's caple to the new card, and used the correct port when plugging it in? In my experience Cards with multiple ports; ie 1x dvi & 1x vga, 2x dvi/vga, etc, has the primary display set to the port on the right when looking at the back of your tower/case.
Also something I missed yesterday in my post. I assume you are using the Onboard video to get back into windows to check out the yellow "?"* at Mutimedia Controller. BTW the yellow ? and red ! are; from what I remmeber of my tech. days, are called "bangs".
If thats the case, then I have a strong feeling you haven't disabled your onboard video properly. Also, you can double click on the divice that is showing a bang in your multimedia controller and more information will be given as to what the issue is. In addition to this, check out your Device manager and see if there is a bang there. The Device manager Is a complex tool for identifying hardware issues, it does however provide the most information; from a software standpoint, for identinfing new hardware installation problems.
Secondly, try searching the forums and google for "How to" guids or tutorials that can guid you through the process of adding a new GPU to a Mainboard with Onboard video. Your search should be limited to ither your mainboard or to your new gpu and mainboard.