how can I tell if my 7jp4 is dead?

[Adam]

I have to get the transformers out of the chassis, just to see behind them so I can see how they are connected. After looking at the set as much as I did I had assumed the modifications were unfinished, it was fixed to the point where the HV and sweep circuits worked, and he stopped there. It does not seem possible to me to have as much of this set wired in series as it is (at least the 6 rf/if tubes through the video amp), and have it connecting to either the 6v or the 24v transformer and even getting as much voltage at the filaments as it is. If it goes to the 120AC, then as not all of the tubes are still in a series string, and there is no replacement for the ballast tube, then the voltage at these tubes would be too high. I would think if one were to wire the set with filament transformers one would just put all the 6v tubes parallel to the 6v transformer, 12 volt tubes parallel to the 12v transformer, and dispense with the series strings entirely. I was also considering getting a 12v. transformer and doing this.
There should be a schematic of the original filament circuit and the rf section here, later I will try to see if I can draw in the modifications.