Sony ICFCD-873-L Service manual
ICF-CD873L
SERVICE MANUAL
Ver 1.0 1999. 05
SPECIFICATIONS
AEP Model
UK Model
Model Name Using Similar Mechanism CFD-550
Optical Device Name KSM-213BAN
Optical Pick-UP Name KSS-213B
MICROFILM
Supplied accessories:
Instruction manual (1)
FM/MW/LW CD CLOCK RADIO
TABLE OF CONTENTS
1. SERVICING NOTES............................................... 3
2. GENERAL ................................................................... 4
CAUTION
Use of controls or adjustments or performance of procedures
other than those specified herein may result in hazardous radiation exposure.
3. DISASSEMBLY ......................................................... 5
4. POWER CORD SETTING................................... 7
5. ELECTRICAL ADJUSTMENTS
Tuner Section .................................................................. 8
CD Section ...................................................................... 9
Main Clock Section......................................................... 11
6. DIAGRAMS
6-1. Block Diagram – CD Section – ..................................... 13
6-2. Block Diagram – TUNER Section – ............................. 15
6-3. Block Diagram – MAIN Section – ................................ 17
6-4. Printed Wiring Boards – MAIN Section – .................... 22
6-5. Schematic Diagram – MAIN Section –......................... 25
6-6. Schematic Diagram – POWER SUPPLY Section –...... 30
6-7. Printed Wiring Boards
– POWER SUPPLY Section – ...................................... 33
6-8. IC Pin Function Description ........................................... 39
7. EXPLODED VIEWS ................................................ 41
8. ELECTRICAL PARTS LIST ............................... 45
This appliance is classified as a CLASS 1 LASER product.
The CLASS 1 LASER PRODUCT MARKING is located on
the rear exterior.
Laser component in this product is capable of emitting radiation
exceeding the limit for Class 1.
The following caution label is located inside the unit.
SAFETY-RELATED COMPONENT WARNING!!
COMPONENTS IDENTIFIED BY MARK ! OR DOTTED
LINE WITH MARK ! ON THE SCHEMATIC DIAGRAMS
AND IN THE PARTS LIST ARE CRITICAL TO SAFE
OPERATION. REPLACE THESE COMPONENTS WITH
SONY PARTS WHOSE PART NUMBERS APPEAR AS
SHOWN IN THIS MANUAL OR IN SUPPLEMENTS PUBLISHED BY SONY.
– 2 –
SECTION 1
CF2
CF3
mark
SERVICING NOTES
NOTES ON HANDLING THE OPTICAL PICK-UP
BLOCK OR BASE UNIT
The laser diode in the optical pick-up block may suffer electrostatic break-down because of the potential difference generated
by the charged electrostatic load, etc. on clothing and the human
body.
During repair, pay attention to electrostatic break-down and also
use the procedure in the printed matter which is included in the
repair parts.
The flexible board is easily damaged and should be handled with
care.
NOTES ON LASER DIODE EMISSION CHECK
The laser beam on this model is concentrated so as to be focused
on the disc reflective surface by the objective lens in the optical
pick-up block. Therefore, when checking the laser diode emission, observe from more than 30 cm away from the objecti ve lens.
CHUCK PLATE JIG ON REPAIRING
On repairing CD section, playing a disc without the CD lid, use
Chuck Plate Jig.
• Code number of Chuck Plate Jig: X-4918-255-1
HOW TO CHANGED THE CERAMIC FILTERS
This model is used two ceramic filters of CF2 and CF3.
You must used same type of color marked ceramic filters in order
to meet same specifications.
Therefore, the ceramic filter must changed two pieces together
since it’s supply two pieces in one package as a spare parts.
Mark Center frequency
red 10.70 MHz
blue 10.67 MHz
orange 10.73 MHz
black 10.64 MHz
white 10.76 MHz
Flexible Circuit Board Repairing
• Keep the temperature of the soldering iron around 270 ˚C during repairing.
• Do not touch the soldering iron on the same conductor of the
circuit board (within 3 times).
• Be careful not to apply force on the conductor when soldering
or unsoldering.
LASER DIODE AND FOCUS SEARCH OPERATION
CHECK
1. Open the CD lid.
2. Turn on S424 as following figure.
3. Conf irm that the laser diode emission while observing the objecting lens. When there is no emission, Auto Power Control
circuit or Optical Pick-up is broken.
Objective lens moves up and down once for the focus search.
Insert a precision
screwdriver and
push S424.
Notes on chip component replacement
• Never reuse a disconnected chip component.
• Notice that the minus side of a tantalum capacitor may be damaged by heat.
laser diode
emission
– 3 –
SECTION 2
GENERAL
This section is extracted from
instruction manual.
– 4 –
• This set can be disassembled in the order shown below.
SECTION 3
DISASSEMBLY
Set
Note: Follow the disassembly procedure in the numerical order given.
Upper cabinet
section
CD lid assy
Main board section Optical pick-up section
UPPER CABINET SECTION
3
two flat wires
(CN303, 304)
2
upper cabinet section
CD LID ASSY
4
connector
(CN306)
1
five screws
(P3
2
Open the CD lid assy.
7
Remove the CD lid
assy.
×
14)
1
three screws
(P3
×
3
4
14)
5
screw
(B3
damper
×
10)
spring
(CD open)
1
Pull the button (open).
6
two bosses
– 5 –
MAIN BOARD SECTION
1
2
net assy
3
Pull the button (open).
twelve
claws
7
flat wire
(CN301)
4
Open the CD lid.
5
screw
(B3
7
×
10)
flat wire
(CN402)
1
two claws
OPTICAL PICK-UP SECTION
6
two screws
(PWH2.6
×
2
10)
claw
6
four screws
(P3
×
14)
3
CD chassis
7
optical pick-up
section
6
two screws
(PWH2.6
×
6
10)
8
main board
section
three screws
(P3
×
14)
5
connector
(CN502)
– 6 –
1
4
screw
(BTP3
flat wire
(CN501)
×
8)
SECTION 4
POWER CORD SETTING
Set the power cord as illustrated below, then install the lower cabinet section.
Power Cord
lower cabinet section
– 7 –
SECTION 5
)
)
1 µF
TP8 (VCO)
+
–
frequency counter
33 k
Ω
TP7 (+B)
+
MAIN board
ELECTRICAL ADJUSTMENTS
TUNER SECTION 0 dB=1 µV
[MW/LW]
Setting:
Function : RADIO
Band switch: MW or LW
AM RF signal
generator
30% amplitude
modulation by
400 Hz signal
Output level: as low as possible
[FM]
Setting:
Function : RADIO
Band switch: FM
FM RF signal
generator
22.5 kHz frequency
deviation by 400 Hz
signal
Output level: as low as possible
• Repeat the procedures in each adjustment several times, and the
frequency coverage and tracking adjustments should be finally
done by the trimmer capacitors.
• Remove FM antenna in FM adjustments.
Put the lead-wire
antenna close to
the set.
set
MAIN board
TP12 (FM IN)
0.01 µF
set
MAIN board
TP53 (VT)
2
2
digital voltmeter
100 k
Ω
level meter
32
Ω
+
–
(headphone) jack (J301
level meter
32
Ω
+
–
(headphone) jack (J301
AM IF ADJUSTMENT
Adjust for a maximum reading on level meter
T1 450 kHz
MW FREQUENCY COVERAGE ADJUSTMENT
Adjustment Part Frequency Display Reading on Digital Voltmeter
L4 531 kHz 2.8 V
Confirmation 1,602 kHz less than 10.5 V
MW TRACKING ADJUSTMENT
Adjust for a maximum reading on level meter
L3-1 621 kHz
CT2 1,404 kHz
LW FREQUENCY COVERAGE ADJUSTMENT
Adjustment Part Frequency Display Reading on Digital Voltmeter
CT4 153 kHz 2.2 V
Confirmation 279 kHz less than 9.5 V
LW TRACKING ADJUSTMENT
Adjust for a maximum reading on level meter
L3-2 162 kHz
CT3 243 kHz
FM FREQUENCY COVERAGE ADJUSTMENT
Adjustment Part Frequency Display Reading on Digital Voltmeter
L2 87.5 MHz 2.1 V
Confirmation 108 MHz 9.7 V
FM TRACKING ADJUSTMENT
Adjust for a maximum reading on level meter
L1 87.5 MHz
CT1 108 MHz
Adjustment Location: MAIN board (See page 12)
FM VCO Adjustment
Setting:
FM RF SSG
0.01 µF
Carrier frequency: 98 MHz
Modulation: 400 Hz, 30% FM modulation
Output level: 0.1 V (100 dB)
MAIN board
TP12 (FM IN)
set
Procedure:
1. Connect the frequency counter to TP7, 8 as shown the figure
below.
2. Tune the set to 98 MHz.
3. Adjust RV1 for 76 kHz reading on the frequency counter.
Specified Value: 75.95 to 76.05 kHz
Adjustment Location: MAIN board (See page 12)
– 8 –
CD SECTION
Note:
Tracking Balance Adjustment and Tracking Gain Adjustment are
done automatically in this set.
TEST MODE
1. Press the CD LID OPEN/CLOSE DET switch (S424) on the
PUSH SWITCH board.
2. Under standby condition (when the clock appears in the display), short the BP (CD TEST AUTO).
Note: If the power is supplied to the microprocessor once, it is backed up
for 3 minutes, therefore the TEST mode will not be activ ated within
3 minutes even if the power is turned on again. In this case, short
instantaneously the BP (CD TEST MANUAL).
3. Press the fl key, and the focus search is repeated.
At this time, check that the optical pick-up objective lens moves
smoothly without a sticking or noise.
4. Load the test disc (YEDS-18: Part No. 3-702-101-01), and perform automatic adjustment after the focus search succeeded.
5. After automatic adjustment is finished, move the sled motor
to the center. At this time, keep pressing the + and =
keys to confirm that optical pick-up mov es smoothly via most
inside track → most outside track → most inside track without a sticking or noise.
6. Confirm the traverse waveform.
7. Press the [WAKEUPTRACK] key.
8. The tracking servo and the sled servo are turned on, the mute
is cancelled.
9. Playback the 2nd track.
10. Adjust the RF and jitter waveforms.
Connecting points: MAIN Board (See page 12)
Focus Bias Adjustment
This adjustment is to be done when the optical block is replaced.
Connection:
oscilloscope
(AC range)
MAIN board
TP503 (RF)
TP504 (VREF)
+
–
Adjustment Procedure:
1. Connect the oscilloscope to TP504 (VREF) and TP503 (RF)
on the MAIN board.
2. Insert the test disc (YEDS-18: Part No.3-702-101-01) and press
fl key to play.
3. Move the optical pick-up to the music area on the disc to enable easy visibility of the eye pattern by + or = key
pressing.
4. Adjust RV501 so that the 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.
• RF signal reference waveform (eye pattern)
VOLT/DIV: 0.2 V
TIME/DIV: 500 ns
±
0.5 Vp-p
1.3
When observing the eye pattern, set the oscilloscope
for AC range and raise vertical sensitivity.
Adjustment Location: MAIN Board (See page 12)
– 9 –
Focus Gain Adjustment
A frequency response analyzer is necessary in order to perform
this adjustment exactly.
However, this gain has a margin, so even if it is slightly off, there
is no problem. Therefore, do not perform this adjustment.
Focus gain determines the optical pick-up follow-up (v ertical and
horizontal) relative to mechanical noise and mechanical shock
when the 2-axis device operate.
However , as these reciprocate, the adjustment is at the point where
both are satisfied.
• When gain is raised, the noise when the 2-axis device operates
increases.
• When gain is lowered, mechanical shock and skipping occurs
more easily.
• When gain adjustment is off, the symptoms below appear.
Procedure:
1. Keep the set horizontal.
If the set is not horizontal, this adjustment cannot be per-
(
formed due to the gravity against the 2-axis device
2. Insert the test disc (YEDS-18) and press the fl button.
3. Connect the oscilloscope BT (FEO) and TP504 (VREF) on
the MAIN board.
4. Adjustment RV502 on the MAIN board so that the w a veform
is as shown in the figure below.
VOLT/DIV: 100 mV
TIME/DIV: 2 mS
100 mV
)
Symptoms
• The time until music starts becomes longer for
STOP → PLAY or automatic selection.
(=, + buttons pressed)
(Normally takes about 2 seconds)
• Music does not start and disc continues to
rotate for STOP → PLAY or automatic
selection.
(=, + buttons pressed)
• Sound is interrupted during PLAY.
Or time counter display stops progressing.
• More noise during 2-axis device operation
Gain Focus
low
–
–
high
The following is a simple adjustment method.
– Primary Adjustment –
Note: Since exact adjustment cannot be performed, remember the posi-
tions of the controls before performing the adjustment. If the positions after the primary adjustment are only a little different, return
the controls to the original position.
Connection:
oscilloscope
MAIN board
BP (FEO)
TP504 (VREF)
+
–
0 V
• Incorrect Examples (DC level changes more than on adjusted
waveform)
low focus gain
high focus gain
VOLT/DIV: 100 mV
TIME/DIV: 2 mS
200 mV
0 V
VOLT/DIV: 100 mV
TIME/DIV: 2 mS
75 mV
0 V
Adjustment Location: MAIN Board (See page 12)
– 10 –
MAIN CLOCK SECTION
Main Clock Adjustment
Connection:
MAIN board
TP (+5 V)
TP401 (X2)
TP GND (SHIELD)
adjustment
jig
+5
OUT
IN
GND
GND
10 : 1 probe
Adjustment jig:
+5 V
IN
GND
+
0.5 pF
47 uF
1 M
1 M
Ω
Ω
Ω
1000 pF
INVERTER
(TC7W04F)
100 k
Ω
OUT
GND
100 k
Procedure:
1. Connect the frequency counter as the above figures.
2. Adjust CT401 for 4.2495 MHz reading on the frequency
counter.
Specified V alue: 4.2490 to 4.2500 MHz
frequency counter
+
–
– 11 –
Loading...