Nope no green light. By the sound that's coming from the rattling I'd describe it as similar to something like shaking a pin in a jar, glass etc.

Well I think I'll open it as I have dissasembled things before and as you mentioned there's always google. Though searching wont be of much use as I tried that and this doesn't seem to be a common problem. Though if you meant looking at pictures of dissasembled ds's then I see what you mean.

I'll probably try dissassembling it tommorow, quite tired today and I don't want to mess any thing up.

Will report back :D

Late reply but so far I'm guessing the battery being dead is ruled out.

There is no distorted sound so that's ruled out.

Though when I shake it, I hear something rattling inside. It seems like something really small though from what I can tell.

Only problem here is I have no idea what to do if I open it, and how to fix whatever problem there is.