I have a crt tv that works great , but whenever I turn it OFF , I can hear static and a series of snap crackle pop sounds coming from back near the tube . Is this a sign of something about to go out , like the flyback ?
That's normal. A lot of sets do that. It's just the charge bleeding off the picture tube. If it's arcing while in operation, then you have a problem, but that trailing crackle at poweroff is pretty normal - many sets do that. If it is making noise while it's on, check and clean around the suction cup anode lead - disconnect it, clean the tube around it and the suction cup, and reattach.
Do you get a big shock when you touch the tube face when it's on? Or just a little tiny shock? If it's big, then the tube isn't grounded to the chassis properly anymore. If it's little, then that's normal...