JBL TLX PS10 (serv.man2) Service Manual ▷ View online
5
Powered Subwoofer
TLX PS10
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).
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.
6
Powered Subwoofer
TLX PS10
pliers, gently heat and remove cut lead from
hole in edge or PCB.
Clean insulator and seating area on back of
panel. Coat both sides of insulator with silicon
(white) thermal compound (unless silicone
rubber pads are provided), position it centered
on back of device with holes aligned. Insert
leads into PCB then place pair over hole in
panel; ensure hole in insulator is aligned. Insert
screw from far side, pass shoulder bushing over
screw and carefully seat shoulder in hole in tab,
add flat washer, lock washer and nut (finger
tight). Center insulator tighten screw first then
solder all three leads in respective slots with full
fillet, being careful not to bridge pads. Use
ohmmeter to verify there is no short from tab of
transistor to panel, or between pads.
Never operate amplifier with load connected
when PC assembly is not attached to panel or
when any of output transistors is not properly
screwed to panel.
After repair, inspect for possible safety hazards,
including loose hardware, missing lock washers, correct
fuse and lead dress of primary wires (these must be held in
position with cable ties so that they cannot touch
secondary components). With ohmmeter, check that
panel is connected to signal ground.
It is essential that the following safety insulation test be
performed prior to returning the Power Sub-Woofer to the
customer, using one of the following methods.
A) Insulation Resistance Test
With a 500VDC Insulation Tester, Check
insulation from the outer metal contact of the
RCA jack (chassis) to the line neutral of AC
cord. Resistance should be >100M
Ω
.
B) Hi-Pot Test
If a UL approved Hi-Pot tester is available, test
line & neutral of AC cord to outer shell of RCA
jack (chassis) at 1100VAC for 2 seconds.
Observe all of instrument manufacturer's
instructions and safety warnings in performing
this test.
Connect sub-woofer system to a music source. Play at
high level while checking for air leaks around panel edge,
driver, panel jacks and controls, and voice coil problems
such as rubbing or loose turns. With the crossover
"frequency" set to 50Hz, very little of the voice content
should be heard.
4. LIST OF SAFETY COMPONENTS
REQUIRING EXACT REPLACEMENTS
F1
Fuse SLOW BLO 1A 250v GMC 20mm
UL approved.
FH
Fuse holder. Use only factory
replacement.
PWR CORD SPT-2 better with polarized plug,
UL appoved wired with the hot side
to fused side. Use with UL approved
panel strain relief only.
XF
transformer. use only factory
replacement.
BD1
Bridge diode. Use only factory
replacement.
C36, 37
6800uF, 63V electronic filter caps.
Be sure replacement part is at least the
same working voltage and capacitance
rating. Also the lead spacing is
important. Incorrect spacing may
cause premature failure due to internal
cabinet pressures and vibration.
K1
Safe operating area relay to protect
output devices. Use only factory
replacement.
R64
5.6
Ω
.5W METAL FILM,
non flammable.
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