The video mentions an aperture lever problem being the cause of this behavior. That doesn't seem the same as the issue you're having.
The first thing that comes to mind in your case is a power supply problem. I'd try a fresh set of batteries first, but it's also possible there's an issue with e.g. a decaying/leaky electrolytic capacitor going on. The reason why I suspect something along these lines is that repeatedly turning the camera on seems to temporarily resolve the issue.