Just because a ride is temporarily closed, or even shutdown for a couple hours, doesn't mean that it is physically broken. Splash is operated by a sophisticated computer system that has the power/responsibility to shutdown the ride should certain conditions arise. IMHO, should somebody (illegally) turn-off the computer warning system until something really breaks, then the ride would probably work normally, until something disastrous happens. A lot of the temporary shutdowns are due to the computers flagging something, shutting down the ride, and the ride needs to be inspected to make sure that everything is working properly.
That being said . . . as attractions age, their sensors and other components can and do age in ways that lead to a higher frequency of safety system triggered breakdowns.
The rumor is that Splash will go down this winter for a major refurbishment, ride systems, show scenes, everything, including the addition of interactive queue elements (supposedly more than Big Thunder, I guess Splash has a longer queue or something). The downside is that it'll probably take as long as Big Thunder's refurb and a bit more. They're also working on upgrading the photo system so that you can choose to get either a traditional photo, and/or a 3D photo, both of which you'll probably have the option of emailing a hi-def copy (copies) to yourself, oh, and yes . . . you'll have to pay extra for 3D glasses, which will be sold as well. I hope they make the traditional photos cheaper/free . . . one can always dream.
If the ride actually physically broke in a major way, it would be down for weeks for emergency repairs.