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If LDS LEDs are all Green (the test
results are good)
If all the LDS LEDs are in green, bright or dim, it
indicates all speakers connected to the amp are
greater than 4 ohm, and no short-circuit exists in
the speaker wiring. The amplifier is safe to drive
the speakers.
The LDS LED of a zone will be in full brightness,
if the trigger switch of that zone is set to ON, or to
MUSIC if the amp is receiving a music signal, or
to 12V if a 12Vdc trigger input is fed to the trigger
input jack. Otherwise, it shall remain in low-level
green.
For those zones with LDS LED in full brightness,
their speakers are automatically connected (by
internal relays); if an LDS LED is dim, the internal
relay of that zone amp does not get connected to
the speaker.
If any of the LDS LEDs are Red it is an
indication that on the offending zone(s)
either the load is too low or a short circuit
exists.
Indicates the speaker connected to that zone amp
either has a short-circuit connection or speaker
impedance that is too low (less than 4 ohms
Fig. 1. Rear Panel of LDS1640 With Eight Zones
typically) for the amplifier. The amplifier repeats
the LDS test on that zone, and the LDS LED keeps
flashing red. The amplifier will not be connected
to the speaker unless the fault condition is
corrected. See the troubleshooting section on page
5 if you encountered this problem.
Input Selection Switches
The zone amplifiers of LDS16-40 are split into two
groups, A and B, with zone 1 to 4 being the A group
and 5 to 8 the B group. Except for zone 1, each
zone contains an input selection switch allowing it
to receive either a GLOBAL main signal or a
LOCAL zone signal. The group A amplifiers can
thus receive a Global-A signal (fed to the zone 1
RCA input) and the group-B amplifiers can receive
either the same group-A signal by setting zone 5’s
input selector to ZONE 1, or receive its own global-
B signal (fed to the Zone 5 RCA input). With the
input selection switch of a zone set to its own zone,
the zone amplifiers receive the signal via the RCA
jacks of that zone.
Trigger Mode Switch
On
Setting the trigger mode switch to the ON position
allows the LDS16-40 to stay ON all the time. None
of the amplifiers will enter the standby mode. The
power to the amplifiers can only be turned off by
turning off the front panel power switch or
disconnecting the power cord.
that this Test Sequence will be performed just
once, immediately after the unit is first powered
up.