I was getting ready for bed last night.  I had just traded some Pokemon with a friend, so my GBA was lying on it.  I picked it up and put it in its usual place atop my GameCube, but I was a little clumsy that late at night, and it dropped on the floor.  I was a little concerned, as that was how my $100 calculator died on me years back (I cracked the screen), but a quick check of the screen assured me that it was fine.  I went to bed worry free.
This afternoon however, I went to play a bit of Pokemon, and I discovered that the screen wasn't displaying properly...  I am getting light and dark patches where particularly dark images should be, the screen is a little darker, but not enough to even see what I am doing.  It doesn't work with either GB or GBA games, and when I shake it, there's a slight rattle.  I don't ever remember a rattle.
I cannot currently afford shipping prices (or repair costs for that matter) to send it to Nintendo for repair.  I would like ot fix it myself if possible.  Does anyone have any experience with a problem such as this, and if so, what are the chances I can do it myself?  I am a little troubled about voiding my warranty by opening it.