Compaq Presario desktop wont power on

My 2005 or 2007 Compaq Presario SR5210NX desktop wont power on. I have unplugged the power cable and let it sit for about 5 minutes. I plugged it back in with no luck. The green flashing light on the back by the power plug still lights up, but when I push the power button...nothing happens. No light, no sound, no nothing. I've seen some quick fix suggestions for laptops with the same issues on this site and I was hoping maybe there might be help for desktops. Thank you for your time and help.