Hi, I am using Windows 7 pro 64 bit and today had a new problem. Switched on laptop and as it got to log in page, the screen went black. When I close the laptop lid and re open it, the screen returns to normal for a few seconds and then goes black again. When plugged into an external monitor, this works fine but laptop screen remains black. Tried system restore and start up in safe mode but had no luck. Tried changing resolution settings but this did not work either. Any solutions? I appreciate even links to solutions. Thanks.