Sony CMT-EH45DAB / HCD-EH45DAB Service Manual ▷ View online
HCD-EH45DAB
10
PRECAUTION
1. Clean the following parts with a denatured-alcohol-moistened
swab:
1. Clean the following parts with a denatured-alcohol-moistened
swab:
record/playback head
pinch roller
erase head
rubber belts
capstan
idlers
2. Demagnetize the record/playback head with a head demag-
netizer. (Do not bring the head magnetizer close to the erase
head.)
head.)
3. Do not use a magnetized screwdriver for the adjustments.
4. After the adjustments, appiy suitable locking compound to the
4. After the adjustments, appiy suitable locking compound to the
parts adjusted.
5. The adjustments should be performed with the rated power
supply voltage unless otherwise noted.
TORQUE MEASUREMENT
Mode
Torque meter
Meter reading
FWD
CQ-102AS
2.0 – 8.0 mN • m
(20 – 80 g • cm)
(0.28 – 1.12 oz • inch)
FWD
Back Tension
Back Tension
CQ-102C
0.15 – 0.6 mN • m
(1.5 – 6.0 g • cm)
(0.021 – 0.083 oz • inch)
FF
CQ-201AS
5.0 – 17.7 mN • m
(50 – 177 g • cm)
(0.7 – 2.48 oz • inch)
REW
CQ-201B
5.0 – 17.7 mN • m
(50 – 177 g • cm)
(0.7 – 2.48 oz • inch)
TAPE TENSION MEASUREMENT
Mode
Torque meter
Meter reading
FWD
CQ-403A
more than 80 g
(more than 2.82 oz)
SECTION 5
MECHANICAL ADJUSTMENTS
SECTION 6
ELECTRICAL ADJUSTMENTS
DECK SECTION 0 dB = 0.775 V
1. Demagnetize the record/playback head with a head
demagnetizer.
2. Do not use a magnetized screwdriver for the adjustments.
demagnetizer.
2. Do not use a magnetized screwdriver for the adjustments.
TEST TAPE
Tape
Signal
Used for
P-4-A063
6.3 kHz, –10 dB
Azimuth Adjustment
RECORD/PLAYBACK HEAD AZIMUTH ADJUSTMENT
Procedure:
1. Mode:
1. Mode:
Playback
set
MAIN board
PHONES jack
(J102)
PHONES jack
(J102)
+
–
level meter
test tape
P-4-A063
(6.3 kHz, –10 dB)
P-4-A063
(6.3 kHz, –10 dB)
2. Turn the adjustment screw and check output peaks. If the peaks
do not match for L-CH and R-CH, turn the adjustment screw
so that outputs match within 1dB of peak.
so that outputs match within 1dB of peak.
Screw
position
L-CH
peak
within
1 dB
Output
level
L-CH
peak
R-CH
peak
within
1 dB
Screw
position
R-CH
peak
3. Mode:
Playback
set
test tape
P-4-A063
(6.3 kHz, –10 dB)
oscilloscope
V
H
waveform of oscilloscope
in phase 45
°
90
° 135° 180°
good
wrong
MAIN board
PHONES jack
(J102)
PHONES jack
(J102)
4. After the adjustments, apply suitable locking compound to the
pats adjusted.
HCD-EH45DAB
11
Adjustment Location: Record/Playback/Erase Head
Note: Remove the cassette lid before this adjustment.
Refer to “DISASSEMBLY” (page 6)
TUNER SECTION
FM TUNE LEVEL CHECK
signal
generator
set
Procedure:
1. Turn on the set.
2. Input the following signal from signal generator to FM antenna
1. Turn on the set.
2. Input the following signal from signal generator to FM antenna
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: Use 75 ohm coaxial cable to connect signal generator and the set.
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-
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.
“TUNED” is displayed.
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 indicat-
ed.
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 specifi ed value with the fol-
lowing checks.
lowing checks.
5. Check the focus bias check when optical pick-up block is re-
placed.
FOCUS BIAS CHECK
+
–
–
CD board
TP122 (RFEQO)
TP124 (VC)
oscilloscope
(DC range)
Procedure:
1. Connect oscilloscope to TP122 (RFEQO) and TP124 (VC) on
1. Connect oscilloscope to TP122 (RFEQO) and TP124 (VC) on
the CD board.
2. Press the [
?
/
1
] button to turn the power on.
3. Set the disc (YEDS-18) and press the [CD
u
] button to play-
back.
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.
VOLT/DIV: 200 mV
TIME/DIV: 500 ns
level:
1.2 ± 0.3 Vp-p
Checking Location:
TP124
(VC)
– CD Board (Conductor Side) –
TP122
(RFEQO)
IC101
HCD-EH45DAB
12
SECTION 7
DIAGRAMS
For Schematic Diagrams.
Note:
• All capacitors are in μF unless otherwise noted. (p: pF) 50
• All capacitors are in μF unless otherwise noted. (p: pF) 50
WV or less are not indicated except for electrolytics and
tantalums.
tantalums.
• All resistors are in Ω and 1/4 W or less unless otherwise
specifi ed.
• f :
internal
component.
• C : panel designation.
THIS NOTE IS COMMON FOR PRINTED WIRING BOARDS AND SCHEMATIC DIAGRAMS.
(In addition to this, the necessary note is printed in each block.)
(In addition to this, the necessary note is printed in each block.)
• A : B+ Line.
• Voltages and waveforms are dc with respect to ground
• Voltages and waveforms are dc with respect to ground
under no-signal (detuned) conditions.
– CD Board –
no mark : CD PLAY
– Other Section –
no mark : TUNER
( ) : CD PLAY
[ ] : TAPE PLAY
‹‹ ›› : REC
• Voltages are taken with VOM (Input impedance 10 M
no mark : CD PLAY
– Other Section –
no mark : TUNER
( ) : CD PLAY
[ ] : TAPE PLAY
‹‹ ›› : REC
• Voltages are taken with VOM (Input impedance 10 M
Ω).
Voltage variations may be noted due to normal production
tolerances.
• Waveforms are taken with a oscilloscope.
Voltage variations may be noted due to normal production
Voltage variations may be noted due to normal production
tolerances.
• Circled numbers refer to waveforms.
• Signal path.
F :
F :
TUNER
J
: CD PLAY
E :
TAPE
PLAY
:
REC
f
: AUDIO IN
For Printed Wiring Boards.
Note:
• X : Parts extracted from the component side.
• Y : parts extracted from the conductor side.
• W : indicates side identifi ed with part number.
• f : internal component.
•
• X : Parts extracted from the component side.
• Y : parts extracted from the conductor side.
• W : indicates side identifi ed with part number.
• f : internal component.
•
: Pattern from the side which enables seeing.
(The other layers' patterns are not indicated.)
• Indication of transistor.
C
B
These are omitted.
E
Q
B
These are omitted.
C E
Q
Caution:
Pattern face side:
(Conductor Side)
Parts face side:
(Component Side)
Pattern face side:
(Conductor Side)
Parts face side:
(Component Side)
Parts on the pattern face side seen from
the pattern face are indicated.
Parts on the parts face side seen from
the parts face are indicated.
the pattern face are indicated.
Parts on the parts face side seen from
the parts face are indicated.
Note: The components identifi ed by mark 0 or dotted
line with mark 0 are critical for safety.
Replace only with part number specifi ed.
HCD-EH45DAB
HCD-EH45DAB
13
13
• Circuit Board Location
MAIN board
PANEL board
CD board
PT-AC board
MODULE
(DAB tuner)
(DAB tuner)
• Waveforms
– CD Board –
– CD Board –
IC101 JB (RFi)
(CD play mode)
(CD play mode)
200 mV/DIV, 500 ns/DIV
0.5 to 1.3 Vp-p
IC101 XG (XO)
(CD play mode)
(CD play mode)
1 V/DIV, 20 ns/DIV
59.1 ns
3.3 Vp-p
RB
Q507 (Base)
2 V/DIV, 5
μs/DIV
14.6
μs
4.4 Vp-p
RT
Q507 (Collector)
5 V/DIV, 5
μs/DIV
14.6
μs
10 Vp-p
XT
IC701 PT (X1)
1 V/DIV, 50 ns/DIV
181 ns
2.7 Vp-p
XB
IC701 RG (X3)
1 V/DIV, 10
μs/DIV
30.5
μs
2.8 Vp-p
– MAIN Board –
– PANEL Board –
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