I've got a Dell laptop (an Inspiron 9300) here with a corrupted LCD
display.

Quick and awful (sorry) photo he http://www.patooie.com/temp/laptop.jpg

I think the display is divided up into (16 or thereabouts) vertical
sections; from the left, the 1st is permanently white, the 3rd and 4th
vary (sometimes flickering, sometimes several white bars as in the photo,
sometimes blank), and the remaining sections have a few vertical colored
lines of single-pixel width.

The display is fine via an external monitor; it's just the internal LCD
display which is scrambled.

I've dismantled the lid and taken the panel out. Reseating the connector
for the video feed (and wiggling the cable etc.) doesn't change anything,
nor does some careful poking around of the connections between the LCD's
control PCB and the LCD surface itself.

What I'm wondering is if it's worth my dismantling the bottom portion of
the laptop in case there's a cabling or other fault on the main system
board - or if this is clearly a case of a faulty LCD panel (and most
likely in the controller IC on the panel's PCB, I'd assume)? Although the
external video works and the internal doesn't, I'm not sure if that's
enough of a test to indicate an LCD problem - for all I know the video
path is more complicated than that and there's other stuff between the
GPU and the LCD (which isn't present between the GPU and external
connector).

I paid $5 for this thing, thinking I'd keep the hard disk as a spare for
another slightly-older Inspiron that I still use occasionally and junk
the rest, but I was surprised to find that everything seems to be working
apart from the internal display; I don't know if I'd want to take the
chance on buying a new panel for it, but if folk think there's a chance
that the fault is in the lower section then I'll probably dismantle it
further...

cheers

Jules