Berea, OH
Quoted from rlbohon3:So I just started a restoration on a Twilight Zone and one of the things I've noticed is that there is no (zero) sound coming from the woofer speaker in the cabinet, while the two backbox speakers seem to be working fine. If I disconnect a wire to the cabinet speaker, sound goes away (to be expected per the circuit), but how is there no sound coming from the cabinet speaker while it's definitely part of the circuit to run the backbox speakers?
Is this just a symptom of a dead, non-moving speaker, even though it still completes the circuit for the other speakers? Or, is this a sign of a dead cap or other component that feeds the cabinet speaker?
Thoughts?
The backbox speakers and cabinet speakers are separate circuits from the audio amplifier out. Some things to check:
1. Ohm out/continuity check from speaker terminals back to J1 of the sound board. You could have a broken wire, even one internally broken in the insulation jacket.
2. Check speaker ohms with a DMM/ohm meter. Could be a dead speaker.
3. Check J1 male/female pins, could be a failed crimp connector on the plug, or cracked solder connection to male header pins on the sound board.
4. If all the above checks out, then the next place to investigate is the sound board itself (the TDA2030 Amplifier component can fail for one) otherwise you'll need advanced skills to troubleshoot audio amplifier with an oscilloscope.
