Check out the voice coil in that speaker, these early transistor radios had another problem when the voice coil open up and the radio was left on it would short out the output transistor then burn up a fuse resistor first find out if the voice coil is open but don't leave the radio turned on, check it with a VOMA meter ,with a good speaker you should here a "thump" in the speaker when the radio is turned on that would mean your output in the radio is OK, BILL