So, if the tubes arent glowing, It's not a cap problem. The filaments of the tubes are all in a series string. Its just like prewar christmas lights, if one goes out they all go out.
There is a thing called Kirchoff's Law, it says that "the sum of all the voltages in a circuit will always equal zero". What this means in plain english is that all the voltages in the string will add up to the source voltage.
Also, (thanks to ohms law) whichever part of the string has the highest resistance will have the highest voltage across it. This is always true, even if the radio is broken or shut off.
Set the meter up for AC volts, and something higher than 150.
So, chassis upside down, plugged in and turned on, (careful
) and check the supply voltage. Probably 110, or 120 or something.