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Appendix A: Service Information
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) to get some
ideas or contact our technical support heroes. 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 line cord is securely seated in the
line cord socket and plugged all the way into the
AC outlet.
• Make sure the AC outlet is live (check with a
tester or lamp).
• Is the POWER switch in the ON position?
• Are the power LEDs on the front and rear panel
illuminated? If not, make sure the AC outlet is
live. If so, refer to “No Sound” below.
• If the power LEDs are not illuminated, and you
are certain that the AC outlet is live, it is possible
the fuse has blown.
To remove and replace the fuse:
1. Disconnect the power cord from the IEC socket.
2. Remove the fuse drawer by prying it open with
a small screwdriver. It will slide all the way out.
3. Remove the fuse and replace it with an
equivalent-type fuse.
115 VAC unit: 6.3 amp slo-blo (T6.3AL/250 V)
230 VAC unit: 3.15 amp slo-blo (T3.15AL/250 V)
4. Replace the fuse drawer by pushing it all the way
back into the IEC socket.
If two fuses blow in a row, then something is very wrong.
Try a different outlet in a totally different location. If fuses
continue to blow, see the “Repair” section on the next page
to find out what to do.
No Sound
• Are the power LEDs on the front and rear panel
illuminated?
• Is the LEVEL control turned up?
• Is the signal source turned up? Make sure the
signal level from the mixing console (or whatever
device immediately precedes the loudspeaker) is
high enough to produce sound.
• If it’s a stereo pair, try switching them around.
For example, if a left speaker is presumed dead,
switch the left and right cords at the speakers. If
the problem switches sides, it’s not the TH-12A. It
could be a bad cable, or no signal from the mixer.
Bad Sound
• Is the input connector plugged completely into
the INPUT jack?
• Is something connected to the THRU jack? Try
unplugging it. If the sound improves, whatever
was plugged into the THRU jack may have
affected the signal.
• Is it loud and distorted? Reduce the signal level at
the mixer.
• If possible, listen to the signal source with
headphones plugged into the preamp stage. If it
sounds bad there, it’s not the loudspeaker.
• Too much bass or not enough bass? Move
around the room and see if the bass response
changes. It’s possible your listening position
coincides with a room mode where the
low frequencies either become exaggerated or
nulled. If so, try moving the loudspeakers to a
different position, or moving your listening
position.
FUSE
