Sony trinitron tv - picture tube?

I have a Sony trinitron tv (model KV-32xbr70) that is having problems
first it started having some blue lines at the top of the screen.
Occasionally after it had been running for a while the screen would go black (still had audio) but would be okay if you turned it off and then back on.
today when I turn it on the picture shrank to about half the size of the screen.
Is this the picture tube going out or something else that can be repaired?