Mackie M1200/M1400 User Manual

26

•

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, then
there will be no output from the amplifier.

•

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.

•

Do the M•1200/M•1400’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? (See Appendix E — “Do The
Math: Ohms, Loads and Such

.”)

•

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.

•

Check the polarity of the speaker cable
connections. You may have your positive
and negative connections reversed at
one end of one speaker cable.

Details concerning Warranty Service are

spelled out on the Warranty Card included with
your amplifier (if it’s missing, let us know and
we’ll rush one to you).

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 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:

•

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.

•

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 

.