DeletedUser433 I thought this fixed the issue but apparently it didn't because it would start booting up again when I wasn't looking.
So far, tapping the power button to pause booting has appeared to work for everybody it has been suggested to.
Is it possible that your battery has failed, so that it can't charge?
If you watch it carefully for 30 minutes while it's paused, in which minute does it start booting by itself?