Troubleshooting - Radio Shack MPA-125 Owner's Manual

32-2003.fm Page 15 Tuesday, March 28, 2000 10:45 AM
ˆ

Troubleshooting

We do not expect you to have any problems with your RadioShack MPA-125 100-Watt PA Am-
plifier, but if you do have a problem, this chart might help. If not, take the amplifier to your local
RadioShack store for assistance.
Symptom
No power. The fuse might be blown.
Sound source or speakers not con-
nected correctly.
No sound. Amplifier's MASTER VOLUME
MIC 2
AUX controls set to minimum.
Sound source or speakers not con-
nected correctly.
A microphone or cable might be faulty.
The speaker's wiring might be shorted.
The speakers might be the wrong
impedance.
The speaker's wires might be too
small.
The amplifier might have shut down.
Feedback. FEEDBACK FILTER might need
adjustment.
Microphones or speakers are too close
together.
Possible Cause
,
MIC 1
, ,
MIC 3 MIC 4/PHONO, or CD/
Troubleshooting
Suggestion
Check the amplifier's fuse and replace it
if necessary (see "Replacing the Fuse"
on Page 17).
Check all connections.
,
Adjust MASTER VOLUME
, ,
2 MIC 3 MIC 4/PHONO
Check all connections.
Check all microphones and cables.
Check all connections.
Make sure all connected speakers have
the same impedance rating (see "Con-
necting the Speakers" on Page 8).
Make sure the speaker's wires are 18-
gauge (for wire lengths up to 25 feet) or
16-gauge (for lengths over 25 feet). For
the best results, use the shortest length
of speaker wire possible.
Turn the amplifier off and let it cool.
Make sure the amplifier is properly venti-
lated, then turn it back on.
Turn the amplifier off and let it cool.
Make sure the amplifier is properly venti-
lated, then turn it back on.
Reposition the microphones and speak-
ers.
, ,
MIC 1 MIC
, .
and CD/AUX
15