Manley BACKBONE Mastering Insert Switcher 2003 - present - Manual (Page 17)

TROUBLESHOOTING
NO POWER, NO LIGHTS, NADA - Probably something to do with AC power. Is it plugged in?
Is the mains voltage set correctly for your country? Also, check the fuse on the back panel. A blown
fuse often looks blackened inside or the little wire inside looks broken. A very blackened fuse is a big
hint that a Very Bad Thing occured. Try replacing the fuse with a good one of the same value and size.
If it blows too then prepare to send the unit back to the dealer or factory for repair. The fuse is a protec-
tion device and it should blow if there is a problem. If the unit works with a new fuse, fine.
LIGHTS BUT NO SOUND - First, if you have gear plugged into the BACKBONE’s inserts, take
each one out of circuit by pressing whichever insert buttons are lit to turn them off. Remember, the
BACKBONE’s inserts are wired in series, which means that if one piece of gear is muted AND se-
lected into the signal path, everything after it won’t get any signal, including your speakers. This also
means if you have an empty insert (no piece of outboard gear connected to it at all) and select this insert
on the front panel, your signal will disappear...
Next, try disengaging all of the BACKBONE’s active stages: this means GAINS, SUM-DIF, and
MIX/FADE. If there is a problem with one of these active boards, it could cause signal to disappear or
be otherwise altered.
Also try checking the signal from the output labeled “SEL INPUT” on the rear of the BACKBONE
- this output is hard-wired directly from your selected source. If this is muted as well, you might want
to check your source into the BACKBONE and make sure there’s a signal going in.
***IMPORTANT NOTE*** Your Manley Mastering BACKBONE was designed to interface
primarily with fully balanced equipment. It is happiest that way. It is also fine with recieving
signal FROM an unbalanced unit, but matters are complicated when the BACKBONE tries
to output signal TO an unbalanced unit.
If you intend to use any unbalanced gear with your BACKBONE, you must ensure that Pin
3 is floating, not grounded. Grounding Pin 3 can potentially cause damage to the BACK-
BONE, and will likely introduce unwanted noise into the signal path. By floating Pin 3, you
can safely utilize unbalanced equipment - but remember that in this scenario, signal level
will drop by 6 dB.
(Note: this applies to ALL outputs of the BACKBONE, including the ELCO/DB25 snakes.)
There is one situation where you can always drive an unbalanced input from your BACK-
BONE. Because Insert 8 is positioned AFTER your ouput gains, if your Insert 8 has trans-
former outputs (or idiot-proof transformer-like outputs), that processor would effectively act
as the output amplifier and be much more tolerant of unbalanced lines connected to your
BACKBONE’s output XLRs.
All things considered, we recommend sticking with balanced gear after your BACKBONE to
avoid complications.
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