Sony ICF-CD855 / ICF-CD855L Service Manual ▷ View online
13
ICF-CD855/CD855L
AM IF ADJUSTMENT
Adjust for a maximum reading on level meter
T1
450 kHz
AM VCO VOLTAGE ADJUSTMENT (ICF-CD855)
Adjustment Part
Frequency Display
Reading on Digital Voltmeter
L4
530 kHz
1.0
±
0.1 V
Confirmation
1,710 kHz
5.3
±
0.7 V
AM TRACKING ADJUSTMENT (ICF-CD855)
Adjust for a maximum reading on level meter
L3
620 kHz
CT3
1,400 kHz
MW VCO VOLTAGE CONFIRMATION (ICF-CD855L)
Frequency Display
Reading on Digital Voltmeter
531 kHz
1.0
±
0.5 V
1,611 kHz
5.2
±
0.6 V
MW TRACKING ADJUSTMENT (ICF-CD855L)
Adjust for a maximum reading on level meter
L3-1
621 kHz
CT3
1,404 kHz
LW VCO VOLTAGE ADJUSTMENT (ICF-CD855L)
Adjustment Part
Frequency Display
Reading on Digital Voltmeter
Confirmation
153 kHz
0.6
±
0.3 V
L4
279 kHz
5.0
±
0.1 V
LW TRACKING ADJUSTMENT (ICF-CD855L)
Adjust for a maximum reading on level meter
L3-2
162 kHz
CT5
261 kHz
FM IF ADJUSTMENT
Adjust for a minimum reading on level meter
T2
10.7 MHz
FM VCO VOLTAGE ADJUSTMENT
Adjustment Part
Frequency Display
Reading on Digital Voltmeter
L2
108 MHz
3.0
±
0.2 V
Confirmation
87.5 MHz
1.3
±
0.3 V
FM TRACKING ADJUSTMENT
Adjust for a maximum reading on level meter
L1
87.5 MHz
CT1
108 MHz
Adjustment and Connecting Location:
TUNER and MAIN board (See page 14)
TUNER and MAIN board (See page 14)
TUNER SECTION
0 dB=1
µ
V
[AM]
Setting:
Function: RADIO
Band: AM or MW or LW
Function: RADIO
Band: AM or MW or LW
[FM/TV/WEATHER]
Setting:
Function: RADIO
BAND button: FM
Function: RADIO
BAND button: FM
• Repeat the procedures in each adjustment several times, and the
tracking adjustments should be finally done by the trimmer ca-
pacitors.
pacitors.
• Remove FM antenna in FM adjustment.
AM RF signal
generator
30% amplitude
modulation by
400 Hz signal
Output level:
as low as possible
modulation by
400 Hz signal
Output level:
as low as possible
Put the lead-wire
antenna close to
the set.
antenna close to
the set.
+
–
–
level meter
set
8
Ω
MAIN board
CNP304 pin
CNP304 pin
2
MAIN board
CNP304 pin
CNP304 pin
1
FM RF signal
generator
22.5 kHz frequency
deviation by 400 Hz
signal
Output level:
as low as possible
deviation by 400 Hz
signal
Output level:
as low as possible
+
–
–
level meter
MAIN board
CNP304 pin
CNP304 pin
2
MAIN board
CNP304 pin
CNP304 pin
1
set
8
Ω
0.01
µ
F
TUNER board
TP (GND)
TP (GND)
TUNER board
TP (ANT)
TP (ANT)
digital voltmeter
TP (VT)
TP (GND)
100 k
Ω
TUNER board
SECTION 5
ELECTRICAL ADJUSTMENTS
14
ICF-CD855/CD855L
Adjustment and Connecting Location:
L4
AM VCO Voltage Adjustment (CD855)
LW VCO Voltage Adjustment (CD855L)
L2
FM VCO Voltage Adjustment
MW Tracking Adjustment
(CD855L)
(CD855L)
L3-1
CT3
LW Tracking Adjustment
(CD855L)
(CD855L)
CT5
L3-2
FM Tracking Adjustment
T1 AM IF Adjustment
T2 FM IF Adjustment
L1
CT1
CT1
AM Tracking Adjustment
(CD855)
(CD855)
L3
CT3
– TUNER BOARD (Component Side) –
– TUNER BOARD (Conductor Side) –
TP
(VT)
TP
(GND)
TP
(ANT)
CNP304
1
4
4
– MAIN BOARD (Conductor Side) –
ICF-CD855/CD855L
15
15
CD SECTION
Perform all CD section check in the test mode.
FOCUS BIAS CHECK
Procedure:
1. Connect the oscilloscope to TP (RF) and TP (VREF) on the
1. Connect the oscilloscope to TP (RF) and TP (VREF) on the
CD board.
2. Insert the test disc (YEDS-18). (Part No. 3-702-101-01) (CD)
3. While playing the CD, set the CD test mode (Refer to CD
3. While playing the CD, set the CD test mode (Refer to CD
TEST MODE (See page 11)) (Automatic adjustment value is
held at this time).
held at this time).
4. Press the
CD
u
button. (LPC ON) (700 is displayed on the
LCD)
5. Confirm that the 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.
6. Press the
CD
u
button. (LPC OFF) (800 is displayed on the
LCD)
7. Perform confirmation in the same manner as step 5.
8. Press the
8. Press the
OFF
x
button.
9. Press the
[SLEEP]
button in the state where 200 or 100 are
displayed on the LCD, and release the CD test mode.
10. Change the test disc (TCD-W082L). (Part No. J-2502-063-2)
(CD-RW)
11. Perform confirmation in the same manner as step 2 to 7.
• RF signal reference waveform (eye pattern)
Connecting Location:
VOLT/DIV: 0.2 V (with the 10: 1 probe in use.)
TIME/DIV: 500 ns
TIME/DIV: 500 ns
CD:
1.1
1.1
±
0.2 Vp-p (LPC ON)
1.2
±
0.4 Vp-p (LPC OFF)
CD-RW:
1.1
1.1
±
0.2 Vp-p
When observing the eye pattern, set the oscilloscope
for AC range and raise vertical sensitivity.
for AC range and raise vertical sensitivity.
TP
(RF)
TP
(TE)
TP
(VREF)
IC701
IC702
– CD BOARD (Conductor Side) –
ICF-CD855/CD855L
16
16
SECTION 6
DIAGRAMS
6-1.
BLOCK DIAGRAM – CD Section –
A
B
D
F
E
C
I-V AMP
DETECTOR
12
11
17
18
27
SL+
SL–
F–
F+
T+
T–
SPINDLE
MOTOR DRIVE
M702
(SPINDLE)
SLED
MOTOR DRIVE
26
M701
(SLED)
FOCUS
COIL DRIVE
TRACKING
COIL DRIVE
SP+
SP–
3
25
9
19
FIN
TIN
SLIN
SPIN
FOCUS/TRACKING COIL DRIVE,
SPINDLE/SLED MOTOR DRIVE
IC702
LD
PD
LASER DIODE
OPTICAL PICK-UP
BLOCK
(KSM-900AAA)
2-AXIS
DEVICE
(FOCUS)
(TRACKING)
2
1
M
M
7
MUTE
AUTOMATIC
POWER
CONTROL
Q701
8
FIN2
7
FIN1
+
MIX
4
RF
LPF
EQ
PH
BH
10
TIN2
9
TIN1
A/D
SW
LPF
TRACK
JUMP
TBAL
80
LDD
APC
AUDIO
ADJUST
SERVO
PROCESSOR
RUPTURE
DETECT
79
LDS
SW
AGC
D/A
13
FE
15
TE
20
TDO
21
FDO
23
SLDO
22
SPDO
S/H
3
EFMIN
SLISE LEVEL
CONTROL
ERROR
CORRECTION
AUDIO CD
RAM
8FS
DIGITAL
FILTER
INTERPOLATION
MUTE
ATTENUATION
DEEMPHASIS
1 BIT
DAC
42
LCHO
RCHO
LPF
DOUT
AUDIO
OUT
FSEQ
PLL
VCEC
CLV, CAV
CONTROL
FRAME SYNC
DETECT,
PROTECT, INSERT,
EFM DECODE
31
RAM
DRF
67
25
CONT4
72
CONT1
66
∗
RES
65
∗
WRQ
61
CE
62
CL
63
DI
64
DO
RF AMP, FOCUS/TRACKING SERVO,
DIGITAL SIGNAL PROCESSOR, CLV SERVO,
DIGITAL FILTER, D/A CONVERTER
IC701
53 CD DATA-IN
54 CD DATA
55 CD CLK
56 CD CE
50 WRQ
58 XRST
41 DRF
39 FSEQ
40
CD OPEN
(Page 18)
A
SYSTEM
CONTROLLER
IC401
(1/2)
R-CH
GENERAL PURPOSE
PORTS
COMMAND
INTERFACE
INTERFACE
DRF
XOUT
XIN
X701
16.9344MHz
S619
CD LID OPEN/CLOSE
DETECT
CD L-OUT
PD1
PD2
F
E
LD
PD
T+
T–
F+
F–
When the optical pick-up
is inner position
is inner position
ON :
S701
(LIMIT)
45
39
CLOCK
GENERATOR
48
49
• SIGNAL PATH
: CD PLAY
• R-ch is omitted due to same as L-ch.
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