I do not follow exactly what you are saying, but I THINK you mean you have confirmed the power transformer makes the right voltage, and the wiring is correct, and the tubes are good. One can only conclude the sockets are bad - I am assuming the tubes have unbroken guide pins and are therefor inserted in the correct orientation.
Did you in fact measure the AC voltage between A7-A8 and B7-B8, with the tubes inserted and power applied? If not, that would be the ultimate test of correct wiring. If the necessary voltage is present at the tube socket pins, remove the power, disconnect one transformer terminal (again, sorry!) and measure the resistance between A7 and A8, and between B7 and B8, still with the tubes inserted. This will test whether the sockets are connected to the tube pins. If the measured resistance is low, repeat the measurement with the tubes removed just to be certain that there is not a short circuit in the wiring.