Welcome to the board!
Do you hear any sound at all? No hum no hiss, nothing? If that is the case then there are two things I would suggest you check. First is to turn on the amp and carefully check to see if the tubes are getting hot. The ones that will get hottest are the two 6V6 output tubes. If they do in fact get warm, then we can assume that they are getting normal amounts of high voltage. If they remain cold, then the rectifier tube would be suspect. If you still have the old one (5AR4) try and substitute it and see what happens. Of course this assumes that the old one is still working.
If the tubes do get warm, then check the speaker and the speaker wiring. Try twisting the speaker plug in the jack, to see if the metal has become oxidized. Make sure that the wires to the speaker are ok and that the terminals are clean and tight. You can test the speaker with a 9 volt battery, by touching the terminals of the battery across the 1/4 inch plug contacts. If the speaker's voice coil is ok, you will hear a thumping from the speaker.
Try these things and get back to us with your findings.