MACKIE M1400/M1400i - Manual (Page 26)

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APPENDIX A: Service Info
• Is the SHORT LED lit? Turn the POWER
off, check the speaker connections and
make sure that there are no strands of wire
shorting across the speaker terminals.
• Is the HOT TEMP STATUS LED lit?
Make sure there is cool air available at the
front of the amplifier. Make sure there is
room at the sides of the amplifier for warm
air to exit. Allow the amplifier to cool off.
• Are there fuses in the speaker or in-line
fuses in the speaker wire? Check ’em to see
if they’re blown.
• Make sure the speakers are working
properly.
One side is way louder than the other!
• Do the M•1400/M•1400i’s meters
read the same on both sides? If not, your
source signal may be delivering an out-
of-balance stereo signal.
• Are both GAIN knobs set to the same
position?
• Are the speaker(s) impedances
matched?
• Try swapping sides: Turn off the amp,
swap the speaker cables at the amp, turn
the amp back on. If the same side is still
louder, the problem is with your speak-
ers or speaker cabling. If the other side
is louder now, the problem is with the
mixer, the amp, or the line-level cabling.
The stereo music sounds kind of sideways,
and the bass frequencies diminish when
standing center, but get louder as you
approach one side!
• Check the polarity of the speaker cable
connections. You may have your positive
and negative connections reversed at
one end of one speaker cable.
As soon as the music gets loud, the amp
shuts down!
• Check the M•1400/M•1400i’s meters .
Be sure that OL is not lighting up
frequently or continuously.
• Can the amp breathe? The M•1400/M•1400i
amp draws its ventilation air in from the
front and out through the side panels. It
needs plenty of fresh air to stay cool.
Do not block the ventilation ports.
If you think your amplifier has a problem,
please do everything you can to confirm it be-
fore calling for service, including reading
through the following Troubleshooting section.
Doing so might save you from the deprivation
of your Mackie amplifier and the associated
suffering.
Of all Mackie products returned for service
(which is hardly any at all), roughly 50% are
coded “CND” — Could Not Duplicate, which
usually means the problem lay somewhere else
in the system. These may sound obvious to you,
but here are some things you can check:
TROUBLESHOOTING
No power!
• Our favorite question: Is it plugged in?
Make sure the AC outlet is live (check with
a tester or lamp).
• Our next favorite question: Is the POWER
switch on? If not, try turning it on.
• Is the green light next to the power switch
illuminated? If not, make sure the AC
outlet is live. If so, refer to “No Sound”
below.
• The AC line fuse inside the cabinet is
blown. This is not a user-serviceable part.
Refer to “Repair” on the next page to find
out how to proceed.
No sound!
• Are the GAIN controls turned all the
way down? Slowly 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 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 OUTPUT APPLICATION switch is
set to SUBWOOFER , make sure the LOW
CUT FILTER frequency control is set to
OFF or nearly OFF. If it is turned up above
the subwoofer cutoff frequency, the output
from the amplifier will be diminished.