gba SP won't turn on

i just bought a gba sp at a yard sale. it will not turn on or charge, i have taken the battery out and tested it in another sp and it works fine so the battery is not the problem. what else could be causing the console not to work?
The ribbon cable may be loose. Open the SP up and see if it's loose.
that's not it. i have been told it could be a fuse, if that is the case would i be able to find a replacement in an original gba?