1950 Admiral 21D1 No sound, and 2 vertical lines in center of screen?

[Magnavox300]

Trying to figure out why my 1950 Admiral has 2 white lines in the middle of the screen, which breaks up the picture; also has scratchy to basically no sound... always a crackling popping sound in the speaker.... any tips?? Tested all tubes, new capacitors were put in a few years back and resistors were tested... maybe something went? Any tips where to check first??