Appendix A: Service Information - Mackie TH-18S User Manual

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/support) 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?
• Is the power LED on the 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 using a small screwdriver.
It will slide all the way out.
FUSE
115 VAC unit: 6.3 amp slo-blo (T 6.3 A H 250 V)
230 VAC unit: 3.15 amp slo-blo (T 3.15 A H 250 V)
3. Remove the fuse
and replace it with
an equivalent-type
fuse.
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
• Is the power LED on the 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 subwoofer) is
high enough to produce sound.
• If it's a stereo pair, try switching them around.
For example, if a left subwoofer is presumed dead,
switch the left and right cords at the subwoofers.
If the problem switches sides, it's not the TH-18s.
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 an output jack? Try
unplugging it. If the sound improves, whatever
was plugged into the output 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 subwoofer.
• 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 using an alternate polarity switch
position, moving the subwoofers to a different
location in the room, or moving your listening
position.
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