Today while screwing around on my HP desktop, it froze. I turned it off and back on and it starts up but shows nothing...nothing on the screen, and does not sound like it's booting up. The keyboard lights flash, the fans and the HD (I think) start up, but nothing appears on the screen. The monitor is working, the rams sticks are seated properly, removed the CMOS bat., and even removed the lithium BIOS bat. to no avail. I removed and replaced the graphics card and all other pci cards.... nothing. Even checked it with another monitor. I do not think it's the power supply, as the keyboard lights flash and the cd rom lights are a go. I'm thinking it might that the mobo has grounded to the case (probably not) or that I fried something on the mobo itself. I'd like to check out all my options before I send it in to probably replace the mobo. Any suggestions? Thank you in advance.