OK, you have the voltage available for the little green PC board to make your filament voltage, which is good, but that voltage isn't getting to the tubes.
Now, very carefully measure the DC voltage between the black and red wires that leave the green PC board and head up to the tube sockets. My guess is that you have 0V on those wires.
If that's the case, then I would inspect the construction of that PC board, looking for funky joints or missing joints. Also, double check the mounting instructions for the L200 regulator. If the hardware isn't installed perfectly, you'll short the transistor case to the amplifier chassis.
-PB