Hey, my computer keeps having these lines across the screen,

>>351896
Oh, and the brightness often changes

>>351898
time to get a new one

>>351911
Shit

>>351896
That's what TFTs do when they get no signal.

Not "their interface board gets no signal", but "the actual panel gets no signal".

First, cheapest, step is to replace the screen ribbon cable, and see if it fixes it. If not, then it's either the panel or the motherboard, and without a working one of either, there's no easy way to tell.

You can get configurable VGA and DVI panel drivers which are good for troubleshooting panels, but it's probably not worth the time and expense.

>>351898
Very likely the cable: it supplies power to the backlight.

First thing to try is simply accessing the motherboard end of it, and unplug/replugging it.

>>351944
Dubs tells truth