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FRS SERIES AMPLIFIERS
FRS SERIES AMPLIFIERS
Appendix A: Service Information
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 your system and you
must reduce the level from your mixer or signal
source.
• Ensure that no equipment in the signal chain
is being over driven. 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.
Partial Sound (frequency band missing)
• Incorrect EQ settings in the electronic equip-
ment. Ensure all EQ settings and filters on the
mixing console or preamplifier and on other
equipment are set for normal operation. Ensure
level controls on electronic crossovers and as-
sociated amplifiers are correctly set and that all
cables and connections for such equipment are
connected and working properly.
• Loudspeaker not working properly. Swap with a
good one.
• The fuses inside the amplifier may have blown.
These are not a user-serviceable. See next page
about service.
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? Slow-
ly turn them up and see if you hear anything.
• 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