T61 only boots with external VGA?

[liryc]

Hey guys, I have a problem, exactly the same as here http://forum.thinkpads.com/viewtopic.php?t=23726, except for the laptop model, mine's a T61. In simple terms, I replace the LCD ribbon, laptop refuses to boot up. It acts normal for 3 seconds, then shuts down. LCD stays blank. Plug in external VGA, it boots up to the external screen like normal. I hit FN+F7 (External/Internal toggle), it shuts down. Any ideas?

Thanks,
liryc