Connect the power adapter to the Mac. On the MacBook / Pro's keyboard, hold down the Shift+Control+Option keys and the Power button at the same time. Release all keys and the power button at the same time – the little light on the MagSafe adapter may change colors briefly to indicate the SMC has reset.
We need to know exactly what it will do. I would hook it up to an external monitor to try to isolate the problem. What dos it do when you reset the PRAM?
Here's how to reset your PRAM:
Shut down your machine. Yes, all the way down, not sleep or logging out.
Press the power button and then press command-option-p-r. ...
Hold those keys down until your Mac reboots again and you here the startup chime.
Let go of the keys and let your Mac reboot normally.