My Compaq Presario SR5223WM when i turn it on the lights come on the fan over the processor stats turning but it will not bootup. I have no keyboard control and no video at all. The video is built into the motherboard so I install a pci video card and still no video. I also excahnged the memory out and put in new memory and still nothing. Even if I take the memory out it still does the same thing no beeps are coming from the motherboard.
You may have a bad board or power supply, but troubleshooting will be needed to try to narrow it down. You've already tried the ram; see if you can borrow another power supply. If the board is bad; it's probably time for a new computer unless you find your board on ebay for under $80; the windows installation (if original) only works with your branded compaq board.