Tip & How-To about Audio Players & Recorders
The Acoustic Authority A-3780 speaker system was an awesome unit blowing away all other competitors in it's price range. One would pay four or five times more to get similar results. Some owners have even used the system for Karaoke and keyboards on stage (very demanding and not recommended) in small venues. That's the good news.
The bad news is that the parts used failed often, especially in the remote control. But if you own one, here's a few general electronic repair solutions to help keep you up and running.
Problem: Remote won't turn on the speakers.
The power on switch is usually broken. They don't seem to last long.
1 Replace it if you can find one...good luck.
2 Replace with another switch design with a little modification to the remote case.
3 Remove it and resolder wire jumpers where the switch was on the remote board so that the unit is always on unless you unplug it or turn it off using a surge protector. As this system did not have a delay circuit per power on and speakers on it will work the same.
Problem: Scratching noises when changing the volume control on the remote.
Oxidation/wear on the volume potentiometer. Using a electronic contact cleaner will clean it up for awhile.
1 Replacement is best but you probably won't find the part.
2 Keep the remote volume fixed and use the computer volume to adjust.
Problem: Loud buzzing from the speakers. Tests:
1 Do the speakers still play audio even though you hear the buzz?
2 Does the buzz go away and the audio is OK on a headset plugged into the connector on the remote?
If yes then chances are one or both of the large 10,000uf 50v electrolytic capacitors on the main power board in the sub woofer has blown. These are filter capacitors to eliminate AC voltage in the DC. When one fails you can get a loud AC 60 cycle hum at the speakers. Check to see if the capacitors are flat on top. If one or both are bulged upwards then the capacitor has vented the electrolytic fluid and failed. Replace them both even if one failed. They cost $5.00-$20.00 online. You can also find them sometimes in audio power amps/receivers if you have a broken one in the closet.
Problem: No audio, no lighted remote. All connections are correct.
Check all parts on the sub woofer power board for any visual failures. When ceramic capacitors fail they usually blow up. Check resistance on all resistors looking for shorts or opens. Get a DVM with Diode Check (example Fluke 77) and check the diodes. Also check the large power transistors for shorts or opens. Just read the resistance across the transistor pins and see if they all match between each other. The specific value in not important. If one is mostly shorted or open compared to the others then it has failed.
Posted by George... on
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