Read Sony HCD-M70 Service Manual online
HCD-M70
13
13
IC103
TP (RF)
TP (VC)
CD SECTION
Note:
1. CD Block is basically constructed to operate without adjust-
ment.
2. Use YEDS-18 disc (3-702-101-01) unless otherwise indicated.
3. Use an oscilloscope with more than 10 M
3. Use an oscilloscope with more than 10 M
Ω impedance.
4. Clean the object lens by an applicator with neutral detergent
when the signal level is low than specified value with the fol-
lowing checks.
lowing checks.
5. Check the focus bias check when optical block is replaced.
Focus Bias Check
Procedure :
1. Connect oscilloscope to TP (RF) and TP (VC) on the CD board.
2. Press the
1. Connect oscilloscope to TP (RF) and TP (VC) on the CD board.
2. Press the
I/1
button to turn the power on, and press
the
Z
CD
button to open the CD disc tray.
3. Put disc (YEDS-18) in and press the
CD
N
button to play-
back.
4. Confirm that oscilloscope waveform is as shown in the figure
below. (eye pattern)
A good eye pattern means that the diamond shape (
A good eye pattern means that the diamond shape (
) in the
center of the waveform can be clearly distinguished.
Checking Location:
– CD BOARD (Conductor Side) –
+
–
–
BD board
TP (RF)
TP (VC)
TP (VC)
oscilloscope
(DC range)
VOLT/DIV: 200 mV
TIME/DIV: 500 ns
TIME/DIV: 500 ns
level:
1.1
1.1
±
0.2 Vp-p
s
Note:
Confirm each contents of this section first of all. If the results are
not satisfied, do the adjustment.
not satisfied, do the adjustment.
1. The adjustments should be performed with the rated power sup-
ply voltage unless otherwise noted.
2. The adjustments should be performed in the order given in this
service manual.
3. The adjustments should be performed for both L-CH and R-
CH.
REC Bias Adjustment
Procedure:
1. Mode: REC
1. Mode: REC
FUNCTION: VIDEO
2. Mode: Playback
3. Confirm playback the signal recorded in step 1 become speci-
fied values as follows.
If these values are out of specification values, adjust the RV101
(L-CH) and RV201 (R-CH) on the TC board to repeat steps
1and 2.
If these values are out of specification values, adjust the RV101
(L-CH) and RV201 (R-CH) on the TC board to repeat steps
1and 2.
Specified values: Playback output of 315 Hz to playback
output of 10 kHz:
± 0.5 dB
Adjustment Location: TC board
attenuator
set
MAIN board
AUDIO IN (MD/VIDEO) jack (SJ302)
L-CH, R-CH
AUDIO IN (MD/VIDEO) jack (SJ302)
L-CH, R-CH
1) 315 Hz
2) 10 kHz
2) 10 kHz
50 mV (– 23.8 dB)
600
Ω
blank tape
CN-123
CN-123
AF OSC
+
–
–
set
recorded
portion
portion
MAIN board
SPEAKER terminals (SJ301)
L-CH, R-CH
SPEAKER terminals (SJ301)
L-CH, R-CH
level meter
SECTION 5
ELECTRICAL ADJUSTMENTS
0 dB=0.775 V
DECK SECTION
RV101 (L)
RV201 (R)
REC Bias
Adjustment
Adjustment
– TC BOARD (Component Side) –
SECTION 4
TEST MODE
Start
REC pause for 3 seconds
FWD REC
Fast forward
REV Play
REC pause for 3 seconds
REV REC
Rewind
FWD Play
Shut off
Shut off
Shut off
Shut off
1 minute
3 minutes
1 minute
3 minutes
Start
Open the disc tray
Close the disc tray
Play the last track
[COLD RESET]
• The cold reset clears all data including preset data stored in the
RAM to initial conditions. Execute this mode when returning
the set to the customer.
the set to the customer.
Procedure:
1. Turn ON the power.
2. Press three buttons of
1. Turn ON the power.
2. Press three buttons of
x
,
[DSG]
, and
CD
X
simultaneously.
3. The set is reset.
[LIQUID CRYSTAL DISPLAY ALL LIT CHECK
MODE]
MODE]
Procedure:
1. Set to standby state.
2. Press three buttons of
1. Set to standby state.
2. Press three buttons of
x
,
[DSG]
, and
[PLAY MODE/TUNING MODE]
simultaneously.
3. Liquid crystal display are all turned on.
4. To exit from this mode, press the
4. To exit from this mode, press the
I/1
button to turn the power
OFF.
[TAPE DECK AGING MODE]
This mode can be used for operation check of tape deck section.
Procedure:
1. Set a tape in the tape deck.
2. Set to standby state.
3. Press three buttons of
1. Set a tape in the tape deck.
2. Set to standby state.
3. Press three buttons of
x
,
[DSG]
, and
[CD SYNCHRO]
si-
multaneously.
4. The aging is executed in bellow sequence.
5. To exit from the aging mode, press the
5. To exit from the aging mode, press the
I/1
button to turn the
power OFF.
Aging mode sequence:
[CD AGING MODE]
This mode can be used for operation check of CD section.
Procedure:
1. Load a CD disc.
2. Set to standby state.
3. Press three buttons of
1. Load a CD disc.
2. Set to standby state.
3. Press three buttons of
x
,
[DSG]
, and
[REPEAT/FM MODE]
simul-
taneously.
4. The aging is executed in bellow sequence.
5. To exit from the aging mode, press the
5. To exit from the aging mode, press the
I/1
button to turn the
power OFF.
Aging mode sequence:
[CHANGE-OVER MD/VIDEO]
Procedure:
1. Set to standby state.
2. Press the
1. Set to standby state.
2. Press the
[DSG]
and the
[FUNCTION]
buttons simultaneously.
3. The function change over to MD or VIDEO by turns.
[CHANGE-OVER THE AM TUNING INTERVAL]
(Except AEP and UK models)
(Except AEP and UK models)
• The AM tuning interval can be changed over 9 kHz or 10 kHz.
Procedure:
1. Press the
1. Press the
I/1
button to turn the power ON.
2. Select the function “TUNER”, and press the
[TUNER AM]
button to select the “AM”.
3. Press the
I/1
button to turn the power OFF.
4. Change over to 9 kHz:
Press the
[TUNING --]
and the
[TUNER AM]
buttons simulta-
neously.
Change over to 10 kHz:
Press the
Change over to 10 kHz:
Press the
[TUNING +]
and the
[TUNER AM]
buttons simulta-
neously.
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