Appendix A: Service Info; Troubleshooting / Repair - Mackie big knob studio Owner's Manual

Appendix A: Service
Information
If you think your Big Knob 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 and documentation. You may find the answer to
the problem without having to send your Big Knob away.
Troubleshooting
No Power
• Our favorite question. Is it plugged in? Make sure that
the female end of the line cord is securely seated in
the IEC socket of The Power Block and the male end
plugged all the way into a live grounded AC outlet.
Make sure the locking barrel connector at the end
of the cord attached to The Power Block is attached
to the power connector of the Big Knob and securely
tightened. An LED on The Power Block will illuminate
green to indicate success (whether Big Knob is powered
on or not).
• Our second favorite question. Is the rear panel power
switch in the ON position?
• Make sure the AC outlet is live (check with a tester or
lamp).
• Is the power LED on the top panel illuminated? If not,
make sure the AC outlet is live. If so, refer to "No Sound"
below.
• Are all the lights out in your building? If so, contact your
local power company to get power restored.
• If the power LED is not illuminated, and you are certain
that the AC outlet is live, it will be necessary to have the
Big Knob serviced. There are no user serviceable parts
inside. Refer to "Repair" at the end of this section to find
out how to proceed.
No Sound
• Is the power LED on the top panel illuminated? If not,
refer to "No Power" above.
• Are the correct input source select button(s) selected?
Make sure the input source select button is lit.
• Is the signal source turned up? Make sure the signal
level from the selected input source is high enough
to light up some of the input meter LEDs on Big Knob's
top panel.
• Make sure the trim control and level switch for the
selected input(s) are set correctly.
• If there is no sound in the phones or studio outputs:
• Make sure the studio outs on/off button is on.
• Make sure the phones and studio level controls are
turned up.
18
Big Knob Studio & Studio + Monitor Controller | Interface
• If there is no sound in the monitor outputs:
• Make sure the correct monitor select button(s) are
engaged and the trim control for the monitor output(s)
are set correctly.
• Make sure the cable connecting the monitor output to
the active speaker or power amplifier isn't defective and
the amplifier/speaker combination is working correctly.
Bad Sound
• Are the input and output connectors plugged
completely into the jacks? Make sure they are
plugged all the way in.
• Is it loud and distorted? Make sure the trim control
and level switch for the selected input is set correctly.
Reduce the signal level on the input source if possible.
• If possible, listen to the signal with headphones plugged
into the input source device. If it sounds bad there, it's
not Big Knob causing the problem.
• Make sure the trim control for the monitor output is
set correctly and not overdriving the input stage of the
active speaker or amplifier to which it is connected.
Noise/Hum/Buzz
• Check the signal cables between the source(s) and
the Big Knob. Make sure all connections are secure.
These problems usually produce crackling noises,
hum, or buzz. Disconnect them one by one. When
the noise goes away, you'll know which input source
is causing the problem.
• Make sure the signal cable is not routed near AC cables,
power transformers, or other EMI sources (including
wall warts and line lumps!). These sources usually
produce hum.
• Excessive hiss is an indication of an incorrect gain
setting somewhere before the Big Knob.
• Sometimes it helps to plug all the audio equipment into
the same AC circuit so they share a common ground.
Repair
For warranty service, please refer to the warranty
information on page 24.
Non-warranty service is available at a factory-
authorized service center. To locate the nearest service
center, visit www.mackie.com, click "Support" and select
"Locate a Service Center or Distributor". Service for a Big
Knob Passive living outside the United States may be
obtained through local dealers or distributors.
If you do not have access to our website, please call
our Tech Support department at 1-800-898-3211 (normal
business hours, Pacific Time), to explain the problem.
They will tell you where the nearest factory-authorized
service center is located in your area.