That is classic. I'll have to save this video for my vaults. I have seen that problem only a few times, and each time is was because of solder bridges. But since you said its never been opened and never modded I'm unsure as to what the problem could be, unless some foreign object got in there some how and is causing the problem.
I love how you can hear the worm gear slipping on the worm gear shaft and making that zziinngggg noise like one of those pocket bikes going down the road. This cant be good for the plastic worm gear.
Do you get anything on the screen when this is happening? Like does it al least go the to browser screen?