I connected an outboard dvd/cdrw burner via USB to my Acer P200mmx notebook and forgot to turn on on the power switch on the burner before I booted the notebook. When it booted the display had some lines shooting across vertically. Since that time the display has become progressively more corrupted in an intermittent manner, sometimes minor corruption, someitmes unusable, occasionally okay. Now the screen is blank, lit up by the backlight but blank. Through all of this the notebook delivers a normal display to an external CRT.
I suspected I might have damaged the invertor that powers the lcd screen by the excessive electrical load presented when the notebook powered up and attempted to power up the burner through the USB port as well. But in that case I should not be seeing the backlight.
It's also possible the two things are not related. The lappy has fallen 18" to the carpet a couple of times. But the problem first showed only when I booted with the burner connected unpowered.