Thanks but looks like solved. I don't know what gives with this "machine" - this is the 2nd time this has happened and it takes me a while to figure out what's going on. I revisited the pc and heard a humming/buzzing noise. I picked it up to listen more closely and there was def some noise coming from it. I held the power button down for a few and it stopped -- as in turned off! It seems that every time I change the power and sleep settings, this happens. I just recently changed them - then changed them back to what I originally had - I believe it happened one other time as well. So I guess all is well but I don't know why that happens. Thanks.
Also boot was the wrong term I guess - you need power to boot and it looked like I did not have power so would not have been able to follow your suggestion. Do appreciate your help.