Shut off problem

I ran the yum updates the other day on my Fedora OS, everything worked fine
before, but now after a certain amount of time (I think after 10 minutes or
so, the time limit set on my screensaver) my computer will just shut off, as
if someone were to push the power button.
Any way to fix this problem so that it will continue to stay on as it did
before I ran the yum updates?

Thanks in advance.