[iBook] Dim display: inverter or backlight?

[Matthew Surles]

I have a clamshell iBook with a dim display that I'd like to return to
it's former glory.  The right half of the display appears brighter
than the left, but neither half is as bright as it should be.  In the
interests of both time and money, I'd like to replace either the
inverter board or backlight bulb, whichever is faulty, but not both if
I can avoid it.

Are there any symptoms diagnostic of either a dying inverter board or
backlight bulb that would clue me in to which is bad?

Thanks for any help,
-matthew surles