Fan on high, led lights blink, black screen

Hello there!

I have an HP Pavilion G7 1317cl. When I turn it on, the fan sounds like its stuck on high speed, the wireless LED is orange, and the caps lock and num lock white LED's blink. I have tried a hard reboot, taking out the battery (which is dead) rebooted it over 50 times, took it all apart, re seated the hard drive, ram, and all of the ribbons and connections, cleaned out the dust, tried connecting an external monitor up, tried pressing f2 for BIOS, and I have had no success. It still just runs the fan on high, and blinks those LEDs. I hooked up my hard drive to my work PC and was able to copy all of my data over, so I know that my hard drive works. I did notice that before I hit the power button, my screen has kind of a green hue to it. When I hit the power, it turns dark black, but that's it. Has anyone else had this issue? If so, please enlighten me with the fix!

Thank you very much!!