JBL SG 2020 Service Manual ▷ View online
-5-
ESD PRECAUTIONS
Electrostatically Sensitive Devices (ESD)
Some semiconductor (solid state) devices can be damaged easily by static electricity. Such components com-
monly are called Electrostatically Sensitive Devices (ESD). Examples of typical ESD devices are integrated cir-
cuits and some field-effect transistors and semiconductor chip components. The following techniques should
be used to help reduce the incidence of component damage caused by static electricity.
1. Immediately before handling any semiconductor component or semiconductor-equipped assembly, drain off
monly are called Electrostatically Sensitive Devices (ESD). Examples of typical ESD devices are integrated cir-
cuits and some field-effect transistors and semiconductor chip components. The following techniques should
be used to help reduce the incidence of component damage caused by static electricity.
1. Immediately before handling any semiconductor component or semiconductor-equipped assembly, drain off
any electrostatic charge on your body by touching a known earth ground. Alternatively, obtain and wear a
commercially available discharging wrist strap device, which should be removed for potential shock reasons
prior to applying power to the unit under test.
commercially available discharging wrist strap device, which should be removed for potential shock reasons
prior to applying power to the unit under test.
2. After removing an electrical assembly equipped with ESD devices, place the assembly on a conductive sur-
face such as aluminum foil, to prevent electrostatic charge buildup or exposure of the assembly.
3. Use only a grounded-tip soldering iron to solder or unsolder ESD devices.
4. Use only an anti-static solder removal device. Some solder removal devices not classified as "anti-static"
4. Use only an anti-static solder removal device. Some solder removal devices not classified as "anti-static"
can generate electrical charges sufficient to damage ESD devices.
5. Do not use freon-propelled chemicals. These can generate electrical charges sufficient to damage ESD
devices.
6. Do not remove a replacement ESD device from its protective package until immediately before you are
ready to install it. (Most replacement ESD devices are packaged with leads electrically shorted together by
conductive foam, aluminum foil or comparable conductive materials).
conductive foam, aluminum foil or comparable conductive materials).
7. Immediately before removing the protective material from the leads of a replacement ESD device, touch the
protective material to the chassis or circuit assembly into which the device will by installed.
CAUTION : BE SURE NO POWER IS APPLIED TO THE CHASSIS OR CIRCUIT, AND OBSERVE ALL
OTHER SAFETY PRECAUTIONS.
8. Minimize bodily motions when handing unpackaged replacement ESD devices. (Otherwise harmless motion
such as the brushing together of your clothes fabric or the lifting of your foot from a carpeted floor can gen-
erate static electricity sufficient to damage an ESD device).
erate static electricity sufficient to damage an ESD device).
-6-
SPECIFICATIONS
SECTION
SG2020
SG3030
AMP
Output Power
65W+65W (6
Ω
, 2ch, T.H.D 10%)
30W+30W (6
Ω
, 2ch, T.H.D 10%)
Woofer
60W+60W (6
Ω
, 2ch, T.H.D 10%)
Frequency Response(MAIN)
40~25,000 Hz
200~25,000 Hz
Frequency Response(Woofer)
45~120 Hz
Signal-to-Noise Ratio
83dB
83dB
Tuner
FM
Tuning Range(OPTICAL)
87.5 ~ 108 MHz
87.5 ~ 108 MHz
Intermediate Frequency
10.7 MHz
10.7 MHz
Signal-to-Noise Ratio
61/58 dBA
61/58 dBA
(Mono/Stereo, 98MHz)
Frequency Response
Frequency Response
60~10,000 Hz
200~10,000 Hz
AM(MW)
Range(OPTICAL)
522~1,611 kHz or 530~1,720 kHz
522~1,611 kHz or 530~1,720 kHz
Intermediate Frequency
450 kHz
450 kHz
Frequency Response
100~2,000 Hz
200~2,000 Hz
SW(OPTICAL)
Tuning Range
5.8~18.0 MHz
5.8~18.0 MHz
Intermediate Frequency
450 kHz
450 kHz
Signal-to-Noise Ratio(11MHz)
35 dB
35 dB 3
LW(OPTICAL)
Tuning Range
153~281 kHz
153~281 kHz
Intermediate Frequency
450 kHz
450 kHz
Signal-to-Noise Ratio(11MHz)
28 dB
28 dB
CASSETTE DECK
FF, REW Time (C-60)
120 sec.
120 sec.
Frequency Response
125~8,000 Hz
250~18,000 Hz
Signal-to-Noise Ratio
43dB(P/B), 43dB(R/P)
43dB(P/B), 43dB(R/P)
Channel Separation
50dB(P/B), 45dB(R/P)
50dB(P/B), 45dB(R/P)
CD
Frequency Response
40~18,000 Hz
200~8,000 Hz
Signal-to-Noise Ratio
70 dB
70 dB
GENERAL
Power Requirements
Refer to the back panel of the unit.
Refer to the back panel of the unit.
Net Dimensions(WxHxD)
273 x 326 x 344 mm
273 x 326 x 344 mm
Net Weight
? kg
? kg
Speaker System
Type
Bass Reflex 2 Way
Bi AMP
3 Speaker System
(Main Speaker, Super Woofer)
3 Speaker System
3 Speaker System
Impendance
6
Ω
6
Ω
Frequency Response(MAIN)
60~20,000 Hz
140~20,000 Hz
Sound Pressure Level(MAIN)
85 dB/W(1m)
90 dB/W(1m)
Rated Input Power(MAIN)
65 W
30 W
Rated Input Power(SUPER WOOFER)
60 W
Max. Input Power(MAIN)
130W
60 W
Max. Input Power(SUPER WOOFER)
120 W
Net Dimensions(WxHxD)
220 x 326 x 252 mm
220 x 372 x 252 mm
Net Weight
? kg
? kg
: EUROPE : UL
NOTE: Designs and specification are subject to change without notice for improvement.
-7-
ADJUSTMENTS
This set has been aligned at the factory and normally will not require further adjustment. As a result, it is not
recommended that any attempt is made to modificate any circuit. If any parts are replaced or if anyone tam-
pers with the adjustment, realignment may be necessary.
recommended that any attempt is made to modificate any circuit. If any parts are replaced or if anyone tam-
pers with the adjustment, realignment may be necessary.
IMPORTANT
1. Check Power-source voltage.
2. Set the function switch to band being aligned.
3. Turn volume control to minimum unless otherwise noted.
4. Connect low side of signal source and output indicator to chassis ground unless otherwise specified.
5. Keep the signal input as low as possible to avoid AGC and AC action.
2. Set the function switch to band being aligned.
3. Turn volume control to minimum unless otherwise noted.
4. Connect low side of signal source and output indicator to chassis ground unless otherwise specified.
5. Keep the signal input as low as possible to avoid AGC and AC action.
TAPE DECK ADJUSTMENT
1. AZIMUTH ADJUSTMENT
2. NORMAL SPEED ADJUSTMENT
Deck Mode
A Deck Playback
MTT-114
Speaker Out
DECK Screw
Azimuth Screw
Maximum
B Deck Playback
MTT-114
Speaker Out
Azimuth Screw
Maximum
Test Tape
Test Point
Adjustment
Adjust for
Deck Mode
Normal Speed
MTT-111
Speaker Out
VR201
3kHz ± 1%
Hi-Speed
MTT-111
Speaker Out
more than 5.4kHz
A Deck
Hi-Speed
Dubbing Mode
Test Tape
Test Point
Adjustment
Adjust for
Remark
CH1 CH2
Speaker Out
Playback Mode
Head
Test Tape
MTT-114
MTT-114
L ch
R ch
GND
Dual-trace
synchroscope
synchroscope
Electronic
Voltmeter
Voltmeter
L out
R out
Unit
Figure 1. Azimuth Adjustment Connection Diagram
Head
Playback Mode
Unit
Speaker Out
GND
L out
R out
Record/Playback
head
head
Test Tape
MTT-111
MTT-111
Frequency Counter
Figure 2. Normal Speed Adjustment Connection Diagram
3. RECORD BIAS ADJUSTMENT
4. TUNER ADJUSTMENT
-8-
Deck Mode
Rec/Pause
MTT-5511
ERASE HEAD
WIRE(PN402)
L201
60kHz±5kHz (Auto-stop)
85kHz±5kHz (Auto-Reverse)
Test Tape
Test Point
Adjustment
Adjust for
Item
DC Voltage
Checker Pin
TP101, 102
0V±50mV
Test Point
Adjustment
Adjust for
Head
Unit
PN402
GND
Record/Playback
head
head
Test Tape
MTT-5511
MTT-5511
Record/Playback
and Pause Mode
and Pause Mode
Frequency Counter
Figure 3. Record Bias Adjustment Connection Diagram
Unit
Signal Generator
GND
Electronic
OSCILLOSCOPE
OSCILLOSCOPE
FM Antenna
Terminal
Terminal
Speake
Figure 4. Tuner(S curve) Adjustment Connection Diagram
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