JBL PX300.4 User manual

PX300.4
4 CHANNEL
POWER AMPLIFIER
SERVICE MANUAL
JBL Consumer Products
250 Crossways Park Dr.
Woodbury, New York 11797 Rev1 2/2004

CONTENTS
Specifications………………………….…………………..……1
Features…………………………………………………………2
Test Conditions And Notes……………………………………2
Controls/connections…………………………………..………3
Mounting…………………………………………….…..………3
Applications………………………………………..……………4
Typical System Configuration…………………………………5
Troubleshooting……………………………………….……..…6
PCB drawings……………………………………..……………7
Parts List………………………………………………..………9
Block Diagrams……………………………………….………12
Semiconductor Pinouts………………………………………13
Exploded view…………………………………………………16
Schematics……………………………………………….……17
Packing…………………………………………………………26
SPECIFICATIONS
Power Output, 4 Ohms 75W x 4
Power Output, 2 Ohms 150W x 4
Power Output, .Bridged, 4 Ohms 300W x 2
MIN. Speaker Impedance 2 ohm
Frequency Response ..... 11Hz~45KHz, ±1dB
Input Sensitivity (RCA type) 250mV~6V
THD + Noise (4 Ohms) ..... 0.04%
Signal-to-Noise 95 dB
Maximum Current Draw 78A
Fuse Replacement 30Ax2
External Dimensions
Length 12 ¼” (312mm)
Width 17” (432mm)
Depth 2 9/16” (66mm)
JBL continually strives to improve its products. New materials, production methods and design refinements are introduced into existing
models without notice as a routine expression of our design philosophy. For this reason, Power Series Multichannel Automotive
Amplifiers may differ in some respects from their published specifications and descriptions, but will always equal or exceed the original
specifications unless otherwise stated.
PowerAmplifier
PX300.4

Px300.4
(rear panel)
POWER FUSES
GND REM BATT
Px300.4
SPEAKER OUTPUTS SPEAKER OUTPUTS
STEREO
REAR
FRONT
LRLR
BRIDGED
NEON NEON
-
+
+
-
LF
System
+
-
RF
System
Subwoofer
Set REAR
X-OVER MODE to LP
(on input panel)
FLAT HP LP
MODE
Set FRONT
X-OVER MODE to HP
(on input panel)
FLAT HP LP
MODE
Set FRONT
INPUT MODE to ST
(on input panel)
Set REAR
INPUT MODE to MO
(on input panel)
ST
INPUT
MODE
MO
Px300.4
(rear panel)
POWER FUSES
GND REM BATT
Px300.4
SPEAKER OUTPUTS SPEAKER OUTPUTS
STEREO
REAR
FRONT
LRLR
BRIDGED
NEON NEON
+
-
+
-
LR Speaker
RR Speaker
RF Speaker
LF Speaker
+
-
+
-
Set REAR and FRONT
INPUT MODE to ST
(on input panel)
Set REAR and FRONT
X-OVER MODE to FLAT
(on input panel)
FLAT HP LP
MODE
ST
INPUT
MODE
MO
Figure 6. The JBL Px300.4
amplifier is set to stereo mode
to drive front and rear pairs of
full-range speakers.
NOTE: To limit bass sent to
full-range speakers, set
X-OVER MODE to HP. See
page 6 to set FREQ and SLOPE.
Figure 7. The JBL Px300.4
amplifier is set to drive a stereo
component system and a
subwoofer with a nominal
impedance of 4 ohms or greater.
NOTE: To drive a pair of rear
midbass speakers (instead of
subwoofer), set INPUT MODE
to ST, X-OVER MODE to LP,
and use DBO to set HP filter.
APPLICATIONS – Px300.4
The JBL Px300.4 amplifier can be set
up for stereo or tri-mode operation, as
shown in Figures 6 and 7.
NOTE: For simplicity, Figures 6 and 7 do
not show power, remote and input
connections.
PowerAmplifier
PX300.4

TROUBLESHOOTING
SYMPTOM LIKELY CAUSE SOLUTION
No audio No voltage at BATT+ Check voltages at
(POWER LED or REM terminals, amplifier terminals
is off) or bad or no ground with VOM
connection
No audio DC voltage on Amplifier may need
(PROTECT LED amplifier output service; see enclosed
flashes every warranty card for
4 sec.) service information
No audio Amplifier is Make sure amplifier
(PROTECT overheated cooling is not blocked
LED is on) at mounting location;
verify speaker-system
impedance is within
specified limits (see
“Specifications” on the
next page)
No audio Voltage less than 9V on Check vehicle
(PROTECT BATT+ connection charging system for
and POWER defective voltage
LEDs flash) regulator
I-E/OPT LED Amplifier is being Check INPUT
is on all times overdriven LEVEL setting;
(not flashing) see previous page
No audio Voltage more than 16V Check vehicle
(PROTECT or less than 8.5V on charging system for
LED is on) BATT+ connection defective voltage
regulator
Distorted audio Input sensitivity is Check INPUT
not set properly, or LEVEL setting; or
amplifier or source check speaker wires
unit is defective for shorts or grounds
Distorted audio Short circuit in Remove speaker leads
and PROTECT speaker or wire one at a time to locate
LED flashes shorted speaker or
wire, then repair
Music lacks Speakers are not Check speaker
“punch” connected properly connections for
proper polarity
Power Amplifier
PX300.4

TRS-00-00087 TRANSISTOR SMALL SIGNAL PNP KTA1023Y 5 Q16,133,233,333,433
TRS-00-00088 TRANSISTOR SMALL SIGNAL NPN KTC1027Y 4 Q143,243,343,443
TRS-00-00090 TRANSISTOR SMALL SIGNAL PNP KTA1266GR 6 Q1,2,5,6,12.13
TRS-00-00091 TRANSISTOR SMALL SIGNAL PNP KTA1268GR 9 Q4,141,142,241,242,341,342,441,442
TRS-00-00110 TRANSISTOR SMALL SIGNAL NPN KTC3198GR 5 Q11,14,15,152,252
TRS-00-00109 TRANSISTOR SMALL SIGNAL NPN KTC3198BL 1 Q3
TRS-00-00111 TRANSISTOR SMALL SIGNAL NPN KTC3200GR 12 Q131,132,151,231,232,251,331,332,351,431
Q432,451
TRS-00-00073 F.E.T N-CH JFET KTK30AGR 5 Q61,101,201,301,401
DIO-00-00006 DIODE SWITCHING SIGNAL DIODE 1SS133 15 D2,3,4,9,10,61,62,151,251,351
D451,801,802,803,804
DIO-00-00003 DIODE RECTIFIER 1N4004 1 D1
DIO-00-00020 DIODE ZENNER DIODE 1W 15V 1N4744 4 D191,291,391,491
DIO-00-00108 DIODE FAST RECOVERY FR154 8 D51,52,53,54,55,56,57,58
RES-00-00523 RESISTOR METAL FILM 1/5WF 4.7KOHM 1 R27
RES-00-00545 RESISTOR METAL FILM 1/5WF 5.6K OHM 4 R127,227,327,427
RES-00-00589 RESISTOR METAL FILM 1/5WF 9.4K OHM 2 R112,312
RES-00-00399 RESISTOR METAL FILM 1/5WF 10.5K OHM 1 R26
RES-00-00425 RESISTOR METAL FILM 1/5WF 15K OHM 2 R212,412
RES-00-00421 RESISTOR METAL FILM 1/5WF 15.2K OHM 4 R111.211.311.411
RES-00-00467 RESISTOR METAL FILM 1/5WF 22K OHM 4 R131,231,331,431
RES-00-00537 RESISTOR METAL FILM 1/5WF 47K OHM 10 R102,103,113,202,203,302,303,313,402,403
RES-00-00556 RESISTOR METAL FILM 1/5WF 56K OHM 8 R107,108,207,208,307,308,407,408
RES-00-00591 RESISTOR METAL FILM 1/5WF 91K OHM 6 R101,201,301,401,213,413
RES-00-00610 RESISTOR CARBON FILM 1/5WJ 10 OHM 1 R5
RES-00-00660 RESISTOR CARBON FILM 1/5WJ 22 OHM 16 R135,136,145,146,235,236,245,246.335,336
R345,346,435,436,445,446
RES-00-00716 RESISTOR CARBON FILM 1/5WJ 47 OHM 16 R22,23,24,25,36,37,38,39,137,147
R237,247,337,347,437,447
RES-00-00622 RESISTOR CARBON FILM 1/5WJ 150 OHM 4 R151,251,351,451
RES-00-00662 RESISTOR CARBON FILM 1/5WJ 240 OHM 2 R381,481
RES-00-00741 RESISTOR CARBON FILM 1/5WJ 680 OHM 1 R6
RES-00-00756 RESISTOR CARBON FILM 1/5WJ 820 OHM 4 R110,210,310,410
RES-00-00633 RESISTOR CARBON FILM 1/5WJ 1K OHM 20 R7,20,21,34,35,42,109,134,144,209
R234,244,309,334,344,409,434,444,809,812
RES-00-00595 RESISTOR CARBON FILM 1/5WJ 1.2K OHM 6 R28,43,172,272,372,472
RES-00-00598 RESISTOR CARBON FILM 1/5WJ 1.5K OHM 4 R154,254,354,454
RES-00-00602 RESISTOR CARBON FILM 1/5WJ 1.8K OHM 2 R383,483
RES-00-00644 RESISTOR CARBON FILM 1/5WJ 2.7K OHM 4 R148,248,348,448
RES-00-00676 RESISTOR CARBON FILM 1/5WJ 3.9K OHM 5 R2,138,238,338,438
RES-00-00702 RESISTOR CARBON FILM 1/5WJ 4.7K OHM 3 R1,13,14
RES-00-00720 RESISTOR CARBON FILM 1/5WJ 5.6K OHM 16 R116,119,122,125,216,219,222,225,316,319
R322,325,416,419,422,425
RES-00-00734 RESISTOR CARBON FILM 1/5WJ 6.8K OHM 16 R118,124,133,143,218,224,233,243,318,324
R333,343,418,424,433,443
RES-00-00751 RESISTOR CARBON FILM 1/5WJ 8.2K OHM 1 R12
RES-00-00608 RESISTOR CARBON FILM 1/5WJ 10K OHM 38 R3,4,29,62,104,114,115,120,121.126
R128,130,204,214,215,220,221,226.228.230
R304,314,315,320,321,326,328,330.404.414
R415,420,421,426,428,430,805,810
RES-00-00623 RESISTOR CARBON FILM 1/5WJ 15K OHM 6 R10,33,155,255,355,455
RES-00-00630 RESISTOR CARBON FILM 1/5WJ 18K OHM 4 R171,271,371,471
RES-00-00658 RESISTOR CARBON FILM 1/5WJ 22K OHM 10 R8,16,117.123,217,223,317,323,417,423
RES-00-00733 RESISTOR CARBON FILM 1/5WJ 6.2K OHM 1 R807
RES-00-00663 RESISTOR CARBON FILM 1/5WJ 24K OHM 2 R105.205
RES-00-00666 RESISTOR CARBON FILM 1/5WJ 27K OHM 3 R17,806,811
RES-00-00687 RESISTOR CARBON FILM 1/5WJ 33K OHM 2 R9,808
RES-00-00697 RESISTOR CARBON FILM 1/5WJ 39K OHM 2 R382,482
RES-00-00724 RESISTOR CARBON FILM 1/5WJ 51K OHM 1 R31
RES-00-00730 RESISTOR CARBON FILM 1/5WJ 56K OHM 6 R44.45,156,256,356,456
RES-00-00748 RESISTOR CARBON FILM 1/5WJ 75K OHM 4 R801,802,803,804
RES-00-00604 RESISTOR CARBON FILM 1/5WJ 100K OHM 3 R63,106,206
RES-00-00647 RESISTOR CARBON FILM 1/5WJ 200K OHM 2 R380,480
RES-00-00654 RESISTOR CARBON FILM 1/5WJ 220K OHM 1 R61
RES-00-00706 RESISTOR CARBON FILM 1/5WJ 430K OHM 1 R11
RES-00-00278 RESISTOR CARBON FILM 1/4WJ 10 OHM 1 R15
RES-00-00312 RESISTOR CARBON FILM 1/4WJ 220 OHM 2 R18,19
RES-00-00053 RESISTOR CARBON FILM 1/2WJ 4.7 OHM 4
R161,261,361,461