JBL TLX PS12, Руководство по обслуживанию

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5
Powered Subwoofer TLX PS12
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 over
full range while applying lateral and vertical oscillating
forces to locate possible intermittent function. High Level
Inputs should be tested individually both differentially
(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 for
loose extraneous articles which may have been pushed
into front port.
2. REMOVING THE AMPLIFIER.
There are voltages and hot components at many points
in the amplifier which can, if contacted, cause personal
injury. Be extremely careful. Any adjustments or service
procedures that require operation of the amplifier out of its
enclosure should be performed only by trained service
personnel. Refer to PCB drawings for locations of hazards
and familiarize yourself with their locations before starting.
3. TROUBLE SHOOTING AFTER REMOVAL
Verify AC plug is disconnected See WARNINGS in
section 2.
To prevent loose hardware from reducing safety
spacings, it is essential that all hardware be replaced in the
same manner as it was removed, with lock washers under
all nuts, proper torque on screws and thread locking sealer
on the transformer nuts.
If line core, its strain relief, or the AC switch are
replaced, it is necessary to seal them completely to panel
with an approved conformal coating to prevent air
"whistling" through any openings from woofer pressure.
To reduce the risk or electric shock and/or
fire, replace items as marked on schematic
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.
A.)
Check fuse F1. If blown visually check transformer
for discoloration, and large capacitors (C36, C37) for
bulges or venting. Check for shorts in Q3-Q7 with
an Ohmmeter, (see schematic).
B.
With ohmmeter, verify contacts of thermostat are
closed, voice coil of woofer is 3.3 ohms, and
windings of transformer are continuous.
C.
Examine board and wiring for obvious damage,
broken or poorly soldered connections, or
discoloration.
D.
Repair or replace items identified above. Procedures
for replacing power transistors and removing PCB
are as follows:
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.
I) Replacing power transistors:
Clip all 3 leads
near body of transistor. Remove screw and
discard device (keep hardware and insulator).
Holding each lead in turn with needle nose
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.