SP640_
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12| Operating Manual ver. SP640-EN-1.1
TROUBLESHOOTING
Problem
Possible cause (s)
Action
1. No Sound
Amplifier
Connect a known working test speaker to the amplifier outputs. If
there is no sound, check that all the electronics are on, the signal
routing is correct, the source is active, the volume is turned up,
and so on. Correct/repair/replace as necessary. If there is sound,
the problem is in the wiring.
Wiring
Verify that you have connected the correct wire pairs to the
amplifier. Play something at low level through the amplifier (for
example, from a CD player or tuner). Connect the test speaker in
parallel with the malfunctioning line. If the sound level has gone
or is very weak, the line has a short in it (possibly a severe
scrape, pinch, or staple puncture). If the sound level is normal,
the wire is open (possibly a cut wire or a missed connection).
Using the test speaker, move down the line and test each
connection/junction until you find the problem and correct it.
Observe proper polarity.
2. Poor Low
Frequency
Response
Speakers wired out-
of-polarity
When two speakers are connected out of polarity, the low
frequencies will cancel each other acoustically. Carefully observe
the wire markings or tracers on your speaker wires. Verify that
the amplifier (+) terminal is connected to pin 1+ of the NL4
connector and the amplifier (-) terminal is connected to pin 1- of
the NL4 connector.
3. Intermittent
output such as
crackling or
distortion
Faulty Connection
Check all connections at amplifier and speakers to ensure they
are all clean and tight. If the problem persists, it may be in the
amplifier or wiring. See Problem 1 above.
4. Constant
noise such as
buzzing,
hissing,
humming
Defective amplifier or
other electronic
Devices
If the noise is present but no program material is playing, the
likely cause is the signal chain in the electronics. Evaluate each
component as necessary to isolate the problem.
Poor system
grounding or ground
loop
Check and correct the system grounding, as required.
If these suggestions do not solve your problem, contact your nearest LSS dealer or LSS distributor.
