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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
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.
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
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 (
) in the
center of the waveform can be clearly distinguished.
Checking Location:
– CD BOARD (Conductor Side) –
+
–
BD board
TP (RF)
TP (VC)
oscilloscope
(DC range)
VOLT/DIV: 200 mV
TIME/DIV: 500 ns
level:
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.
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
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.
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
1) 315 Hz
2) 10 kHz
50 mV (– 23.8 dB)
600
Ω
blank tape
CN-123
AF OSC
+
–
set
recorded
portion
MAIN board
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
– 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.
Procedure:
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]
Procedure:
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
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
x
,
[DSG]
, and
[CD SYNCHRO]
si-
multaneously.
4. The aging is executed in bellow sequence.
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
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
I/
1
button to turn the
power OFF.
Aging mode sequence:
[CHANGE-OVER MD/VIDEO]
Procedure:
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)
• The AM tuning interval can be changed over 9 kHz or 10 kHz.
Procedure:
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
[]
and the
[TUNER AM]
buttons simulta-
neously.