Part of Laptop LCD screen fades; screen malfunction?

I opened my laptop today to discover the left ~3 inches of my laptop lcd screen significantly less lit than normal. It's dark, and gradually fades to normal brightness. It's very noticeable; the rest of the screen looks great.

Before I decide to purchase a new LCD and replace it myself (I'm told it's easy), I want to check with y'all experts if this is indeed a screen malfunction (backlight burnt out or w/e) that can be remedied w/ a replacement.

Thanks in advance.

Tech specs:
Dell Inspiron 6400/E1505
Screen = 15.4" Widescreen XGA display

Roughly 1 1/2 years old, out-of-warranty

edit: this is w/ the power supply plugged in, already tested rebooting, changing screen res, the standard w/ no go.

edit2: upon a restart, the fade has now spread to half the screen. quite amazing. if the screen becomes homogeneously darker it'll at least be easier on my eyes...

Jam it back in, in the dark.