Sigh... my tv may have died.... Sylvania

[rodmonster]

OK - i screwed up. I had my 1971 Sylvania Console on in the game room and walked off for a few minutes... got caught up in house work and left the house... A few hours later i came back and realized i had left it on...
Now there is no picture at all....
No clue what happened. Nothing at all comes on the screen.
The sound works fine so i know its still getting power - etc...
But being a true novice here still.. I have no idea what to look for.
I have a tube tester and i guess i can check those - but that only tells me if the filament is good....
She is the TV thats in avatar signature block...
Very upset to be quite honest... after spending over 400 dollars to get her running and working... i am kind of bent....