Powered SubwooferARC SUB
BEFORE THIS AMPLIFIER IS PLUGGED IN, make sure its rated voltage corresponds to the voltage of the AC power
source to be employed. Failure to use the correct voltage could cause damage to the amplifier when the AC power cable is
plugged in. Do not exceed the rated voltage by more than 10%; operation below 90% will degrade performance or cause the
unit to shut off.
1. TROUBLE SHOOTING BEFORE OPENING
Check connections, control settings, driver and other
possible external problems. If there is Output, determine if
all controls and Inputs function properly. Rotate Pots overIf line core, its strain relief, or the AC switch are
full range while applying lateral and vertical oscillatingreplaced, it is necessary to seal them completely to panel
forces to locate possible intermittent function. High Levelwith an approved conformal coating to prevent air
Inputs should be tested individually both differentially"whistling" through any openings from woofer pressure.
(signal from "-" to "+" with normal output) and in common
mode (signal from low level ground to both "+" and "-"
shorted together, giving virtually no output). While passing
a signal, corner drop the enclosure a few inches to expose
possible intermittent problems. Check woofer for rubbing of
voice coil or tears in cone or surround. Check cabinet forTo reduce the risk or electric shock and/or
loose extraneous articles which may have been pushedfire, replace items as marked on schematic
into front port.with the safety marking only with the exact
replacements listed in the safety component
list, section 5. If exact replacements are not available,
order them from the factory or an authorized service center.
2. REMOVING THE AMPLIFIER.
A.)CheckfuseF1.Ifblownvisuallychecktransformer
for discoloration, and large capacitors (C36, C37) for
bulges or venting. Check for shorts in Q3-Q7 with
There are voltages and hot components at many pointsan Ohmmeter, (see schematic).
in the amplifier which can, if contacted, cause personal
B.Withohmmeter,verifycontactsofthermostatare
injury. Be extremely careful. Any adjustments or serviceclosed, voice coil of woofer is 3.0 ohms, and
procedures that require operation of the amplifier out of its
enclosure should be performed only by trained servicewindings of transformer are continuous.
personnel. Refer to PCB drawings for locations of hazardsC. Examine board and wiring for obvious damage,
and familiarize yourself with their locations before starting.
broken or poorly soldered connections, or
discoloration.
D. Repair or replace items identified above. Procedures
3. TROUBLE SHOOTING AFTER REMOVAL
for replacing power transistors and removing PCB
are as follows:
Verify AC plug is disconnected. See WARNINGS in
section 2.
Use low power, grounded temperature regulated iron
with small tip such as Weller PTA7 and ESD control.
Use SN63/37 solder 0.032" diameter with "no clean"
flux core, Alpha Metals P2 or equal.
To prevent loose hardware from reducing safetyI) Replacing power transistors: Clip all 3 leads
spacings, it is essential that all hardware be replaced in thenear body of transistor. Remove screw and
same manner as it was removed, with lock washers underdiscard device (keep hardware and insulator).
Holding each lead in turn with needle nose
all nuts, proper torque on screws and thread locking sealer
on the transformer nuts.
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