MACRO range installation manual. Issue 6
The front panel of the power switch may be removed by light leverage to enable lamp replacement. Power for the lamp is derived from a small 18V stabiliser on the Power Management Board.
Failure to illuminate will indicate one of the following:-
a)Lamp failure
b)Neither AC nor DC power to the amplifier
c)Both AC mains and DC fuses on the rear panel have failed
d)Stabiliser circuit has failed
ëERRORí status indicator LED
Illumination of this LED is as a consequence of the overload protection circuit in the power output module being triggered. This could be as a result of the following:
a)A severe overload on the loudspeaker line
b)Transitory saturation of 100V line loudspeaker transformers connected to the 100V line terminals.
c)An electronic fault in the power output module drive circuit.
Illumination resulting from a) or b) will occur only whilst an audio drive signal is present. During periods of illumination the amplifier output will be muted and minimal current will be drawn from the power supply. This condition can be maintained indefinitely without further risk to the amplifier.
ëPOWERí status indicator LED
A three colour LED is used to indicate the integrity of AC and DC power supplies:
Green | AC supply connected |
Red | DC supply connected |
Orange | AC an DC supplies connected |
Power supply failure monitoring
The ëAuxiliaryí output D connector provides the facility to monitor the integrity of both the AC mains and DC standby supplies. Each supply energises a relay with light duty normally open contacts which are taken to pins 13/14 and 15/16. The relays are located
Fig. 10 AC & DC supply connections and monitoring
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