start up issues in snow leopard

I've erased and reinstalled my MacBook pro 2011 original osx snow leopard disk twice, (running Yosemite last) Everything was good again, but when I tried to download updates and restart, it comes back to desktop with nothing else. Didn't really restart at all. I can't do anything but shut it down, and that takes a few seconds holding the button. Before the last time I tried the erase and reinstall, it just stayed on the blue screen until I shut off. That's gone now, but still.....

the mac has been restarting, (with no chime ever) but will not restart when downloading updates. Another thing I've noticed is that when I start up manually I don't get the sign in page. PS I have managed to download the Combo update thought.

I'm trying everything I can before I call Apple.

Should I try resetting NVRAM? Haven't done that yet. If I upgrade to Mountain Lion or if start up isn't working I doubt it.

I also wonder if I'm reinstalling incorrectly. When I choose the disk I want to use for startup disk, I have to rename it. So it is disk 1. I created it from the top drive on the far left. I hope someone has the answers.😢

L