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HCD-GPX33/GPX55/GPX77/GPX88
16
CD SECTION
Note:
1. CD Block is basically constructed to operate without adjustment.
2. Use YEDS-18 disc (Part No. 3-702-101-01) unless otherwise indicat-
1. CD Block is basically constructed to operate without adjustment.
2. Use YEDS-18 disc (Part No. 3-702-101-01) unless otherwise indicat-
ed.
3. Use an oscilloscope with more than 10 MΩ impedance.
4. Clean the object lens by an applicator with neutral detergent when the
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.
5. Check the focus bias check when optical pick-up block is replaced.
FOCUS BIAS CHECK
Procedure :
1. Connect the oscilloscope to CL574 (RFMON) and
1. Connect the oscilloscope to CL574 (RFMON) and
CN509 pin 3 (GND) on the MB board.
2. Press the [
?/1
STANDBY] button to turn the power on, and
press the [CD] button to select CD function.
3. Set disc (YEDS-18) and press the [u] button to playback.
4. Confi rm that oscilloscope waveform is as shown in the fi gure
4. Confi rm that oscilloscope waveform is as shown in the fi gure
below (eye pattern).
A good eye pattern means that the diamond shape (
) in the
center of the waveform can be clearly distinguished.
Checking Location:
-MB Board (Conductor Side)-
-MB Board (Conductor Side)-
+
–
MB board
oscilloscope
(DC range)
CL574 (RFMON)
CN509 pin 3 (GND)
VOLT/DIV: 200 mV
TIME/DIV: 500 ns
level:
1.0 ± 0.25 Vp-p (CD)
SECTION 4
ELECTRICAL CHECK
FM AUTO STOP CHECK
Procedure:
1. Turn the power on.
2. Input the following signal from Signal Generator to FM an-
1. Turn the power on.
2. Input the following signal from Signal Generator to FM an-
tenna input directly.
Carrier frequency : A = 87.5 MHz, B = 98 MHz, C = 108 MHz
Deviation
Deviation
: 75 kHz
Modulation
: 1 kHz
ANT input
: 35 dBu (EMF)
Note:
Please use 75 ohm “coaxial cable” to connect SG and the
set. You cannot use video cable for checking.
set. You cannot use video cable for checking.
Please use SG whose output impedance is 75 ohm.
3. Set to FM tuner function and scan the input FM signal with
automatic
automatic
scanning.
4. Confi rm that input Frequency of A, B and C detected and
automatic scanning stops.
The stop of automatic scanning means “The station signal is
received in good condition”.
received in good condition”.
TUNER SECTION
0 dB = 1 μV
signal
generator
set
+
–
75
CN509
CN110
CL574
pin 3 (GND)
(RFMON)
Ver. 1.1
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