MacBook Pro won't turn on, standby light solid
I have a MacBook Pro 15" which I think is a 2007 model. Last night I left it on and just closed the lid to let it go to sleep, opened the lid this morning and the screen is black and the standby light is on solid, I can't get it to do anything. I even try pressing keys on the keyboard and nothing. I hold the power button to shut it down and then wait a few seconds then turn it back on, the DVD drive makes a noise like normal but thats it nothing on the screen and the standby light is solid. I put the disk that I got with the laptop in to see if I could boot from it and nothing but a stuck DVD in the drive. I tried hooking up an external that I can boot from and it does nothing also. In the past couple of weeks my screen had flashed to a grey color with only the mouse curser showing, I could move the mouse around but that was it. After a reboot both times the computer seemed fine. I'm at a lost, I hope my laptop has not bit the dust, any help would be appreciated. Thanks
MacBook Pro, Mac OS X (10.7.1)