Question: Speaker volume not adjusting
My macbook pro speaker is not adjusting volume from the main output. Sound comes out from Spotify/Dishnetwork, etc. apps but is not allowing me to turn it up.
I'm also trying to back up my system and that's not working either and I just realized I'm on 10.10.5 and can't seem to upgrade.
PLEAASE advise all options. Thanks!
MacBook Pro with Retina display, iOS 11.2, 10.10.5