. If water comes into contact with the system, the battery shorts, and hence the system doesn't turn on – the system's not broken, the battery's just dead (the Li-Ion component's liquid solvent becomes useless and "drains" the power so that it can't recharge). So for a quick fix, there's a chance it'll fix itself if you dry out the battery, or you could simply buy a new one (I just bought one for my brother's SP, they're like a buck or two on Amazon, I don't think Radio Shack sells them anymore though). If it still doesn't work I'd assume you'd want to send it in then, though from own experience, it's much cheaper to bring the Game Boy to a local repair shop than to send it in to Nintendo themselves, if you know a shop that can work with those kinds of electronics, worst case scenario they'll just swap out a few parts; though if they can't find a problem with it or can't fix it, many repair shops (and Nintendo) will just replace the system (for Nintendo at least it ends up being cheaper than fixing it), so if for whatever reason you don't want to part with your current hardware, that'd be something you'd want to bring up with any customer service.