If you can figure out whats wrong with it, can get parts easily, and are handy with a screwdriver, then go for it, but be warned, you take a risk with these sort of things, especially if you don't know the exact problems, I have a 500Mhz G4 that had some missing parts when I bought it, there was no telling what the exact problems were, I thought it would be as simple as replacing the said missing parts...
Wrong.
Turns out the logic board is defective and since this is an AGP model vs a GE, its incredibly difficult to find a replacement that won't rob your wallet so I currently own a big hunk of useless metal and plastic.
So go ahead and attempt to fix it, but be aware of the risks, the last broken Mac I bought to fix up was nothing but sucessful, but I also knew what the problem was in that case, the current G4 was a bit more shady, but that doesn't mean I'm going to stop doing this, if I can find a good deal on a broken Mac, fix it up and sell it then I'm going to go for it if I have some extra ca$h to spare, its a good little side project, but don't think everything's going to go all perfect.
