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FRS Series Amplifiers
FRS Series Amplifiers
Appendix A: Service Information
• Is the signal source turned up? Make sure
the signal level from the mixing console (or
whatever device immediately precedes the
amplifier) is high enough to produce sound in
the amplifier. The SIG LEDs should be blinking
to indicate that signal is present.
• If the speakers are wired for bridge mode, make
sure the amp mode switch is set to bridge.
• If the amplifier has become extremely hot, the
thermal protection circuit may have activated.
Allow the amplifier to cool down and normal
operation should resume.
• Are there fuses in the speakers, or in-line
fuses in the speaker wire? Check to see if
they’re blown.
Distorted Sound
• The power amplifier is clipping. The signal
level is exceeding the limits of the system
and you must reduce the level from the
mixer or signal source.
• The loudspeaker(s) are being overdriven. Turn
down the volume to see if the distortion goes
away. If not, review the owner’s manual for the
loudspeakers to ensure that they are a proper
match for the amplifiers.
• Ensure that no equipment in the signal chain
is being overdriven. For example: input(s)
or summing bus in the mixing console,
equalizers, etc.
• Is the input connector plugged completely
into the jack? Check the speaker connections
and verify that all connections are tight and
that there are no stray strands of wire shorting
across the speaker terminals.
• If possible, listen to the signal source with
headphones plugged into the console. If it
sounds bad there, the problem is not in the
amplifier.
• Loudspeakers not working properly.
If you think your Mackie product has a problem,
please check out the following troubleshooting tips and
do your best to confirm the problem. Visit the Support
section of our website (www.mackie.com/support)
where you will find lots of useful information such as
FAQs, documentation, and user forums. You may find
the answer to the problem without having to send your
Mackie product away.
Troubleshooting
No Power
• Our favorite question: Is it plugged in?
• Make sure the power cord is securely seated in
the IEC socket and plugged all the way into the
AC outlet.
• Make sure the AC outlet is live (check with a
tester or lamp).
• Make sure the front panel power switch is in
the on position.
• Is anything on the front panel illuminated? If
not, make sure the AC outlet is live.
• Are all the lights out in your town? If so, contact
your local power company to get power restored.
• If nothing is illuminated, and you are certain
that the AC outlet is live, it will be necessary to
have your amplifier serviced.
There are no user
serviceable parts inside.
Refer to “Repair” on the
next page to find out how to proceed.
No Sound or Low Output
• Loudspeaker cables or connectors are not wired
correctly or they are faulty. Check all cabling,
referring to these instructions for the correct
connections. The best way to check a suspect
cable is to swap it with a known good cable.
Read the loudspeaker’s input panel to verify
correct cable connections.
• Loudspeaker is not working. Connect the
loudspeaker cable to a known good loudspeaker
leaving all equipment set to the same levels.
If the problem disappears, the loudspeaker is
probably not working correctly.
• Are the channel level controls turned up?
Slowly turn them up and see if you hear
anything.