Electrical Checks - Sony HCD-GTX999 Service Manual

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HDD FACTORY SHIPMENT TEST MODE
The user use areas in HDD are initialized, and the cold reset is
executed.
Note: When this mode is executed, all the MUSIC data including the
DEMO tune in HDD is deleted (The SYSTEM fi le is not deleted).
Execute this mode after it notes it enough when executing it because
all the MUSIC data and CDDB updates that the user recorded are
deleted.
Procedure:
1. In the standby status, press the [ ] button to turn the power
?/1
on.
2. Press three buttons of [x], [GROOVE] and [HDD REC] si-
multaneously.
3. Press the [M]/[m] buttons to select the "OK?", and press the
[ENTER] button.
4. All folder/fi le in the following folders in HDD is deleted.
• ROOT\SYSTEM\CCUDB
• ROOT\MUSIC
5. After initialization ends, the cold reset is executed.
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HCD-GTX999
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CD SECTION
Note:
1. CD Block is basically designed to operate without adjustment. There-
fore, check each item in order given.
2. Use YEDS-18 disc (3-702-101-01) unless otherwise indicated.
3. Use an oscilloscope with more than 10 MΩ impedance.
4. Clean the object lens by an applicator with neutral detergent when the
signal level is low than specifi ed value with the following checks.
RF LEVEL CHECK
CD board
TP216 (RFACO)
TP5 (VC)
Procedure:
1. Connect an oscilloscope TP216 (RFACO) and TP5 (VC) on
the CD board.
2. Turn the power ON.
3. Load a disc (YEDS-18) and playback.
4. Confi rm that oscilloscope waveform is clear and check if RF
signal level is correct or not.
Note: Clear RF signal waveform means that the shape " ◊ " can be clearly
distinguished at the center of the waveform.
RF signal waveform
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E-F BALANCE (1 TRACK JUMP) CHECK
CD board
TP3 (TEI)
TP5 (VC)
Procedure:
1. Connect an oscilloscope to TP3 (TEI) and TP5 (VC).
2. Turn the power ON.
3. Load a disc (YEDS-18) and playback the number 5 track.
4. Confi rm that the level B and A (DC voltage) on the oscillo-
scope waveform.
1 track jump waveform
DVC
level = 1.3 ± 0.6 Vp-p symmetry
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SECTION 5

ELECTRICAL CHECKS

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Connecting and Adjustment Location: CD board
– CD BOARD (CONDUCTOR SIDE) –
oscilloscope
TP5
(VC)
TUNER SECTION
FM TUNE LEVEL CHECK
signal
generator
VOLT/DIV : 200 mV
Procedure:
TIME/DIV : 500 ns
1. Turn on the set.
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2. Input the following signal from signal generator to FM antenna
input directly.
level : 1.1 ± 0.3 Vp-p
Carrier frequency : A = 87.5 MHz, B = 98 MHz, C = 108 MHz
Deviation
Modulation
ANT input
Note: Use 75 ohm coaxial cable to connect signal generator and the set.
oscilloscope
You cannot use video cable for checking.
Use signal generator whose output impedance is 75 ohm.
3. Set to FM tuner function and tune A, B and C signals.
4. Confi rm "TUNED" is lit on the display for A, B and C sig-
nals.
When the selected station signal is received in good condition,
"TUNED" is displayed.
center of
waveform
B
A (DC voltage)
m
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HCD-GTX999
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TP3 TP216
(TEI) (RFACO)
set
9 8 2 9 9
: 75 kHz
: 1 kHz
: 35 dBu (EMF)