[Mondial]

That looks like another early style ceramic cap. It is also an RF bypass connected between the grid and cathode of the 50A5 output tube.

Again, it most likely is not the cause of your problem as the radio will work fine with it disconnected.

To troubleshoot your no audio problem, I would suggest making voltage measurements from each of the tube pins to B- supply and compare with the chart on the schematic. If any voltage reading is significantly different, it can point you to the cause of the problem.

Here is another schematic and service data with voltage measurements. Use the VTVM readings if you are using a digital multimeter.

http://www.nostalgiaair.org/PagesByModel...013584.pdf