Laptop screen blank

[gerardee]

Hi, i need help solving this problem. My T400 screen goes completely blank when it enters windows. It works fine during the start up and I can see the windows loading screen on my laptop. Only starts to go blank on the password entering screen and windows itself

My external monitor still works, but I am unable to switch to an extended display nor am I able to use the laptop as a stand alone. When i plug my external monitor out, my laptop screen is still blank.

I'm running on XP. Tried to update the ATI drivers but still doesn't work.

[Harryc]

Change the laptop LCD screen in BIOS to be the primary boot device.

[gerardee]

In the BIOS, the primary screen is the Thinkpad LCD screen..

Even when I press Fn F7, and try to set the thinkpad screen as the primary display... it just goes blank and my external monitor goes all haywire..

When i plug out my external monitor, my Thinkpad screen refuses to become the primary screen and goes all black.

Anyone has any other ideas?