Sony ICF-M88B - S2 Sports Bicycle Radio User manual

SERVICE MANUAL
FM/AM PLL SYNTHESIZED RADIO
US Model
Canadian Model
SPECIFICATIONS
ICF-M88B
Ver 1.0 2004.05
9-877-839-01
2004E05-1
© 2004.05
Sony Corporation
Personal Audio Company
Published by Sony Engineering Corporation
Battery Life (Approx. hours) (JEITA*)
When using FM AM
Sony alkaline size AA (LR6) 66 84
Sony size AA (R6) 23 31
*Measured by JEITA (Japan Electronics and Information Technology Industries
Association) standards.
The actual battery life may vary depending on circumstances of use.
Time display: 12-hour system
Frequency range:
Band Range Channel step
FM 87.5 - 108 MHz 0.1 MHz
AM 530 - 1 710 kHz 10 kHz
531 - 1 710 kHz 9 kHz
Speaker: Approx. 50 mm (2 inches) dia, 8
Power output: 80 mW (at 10% harmonic distortion)
Power requirements: 3V DC, two size AA (R6) batteries
Dimensions :
Approx. 166.8 ×70 ×95 mm (w/h/d) (6
5
⁄
8 ×2
7
⁄
8 ×3
3
⁄
4
inches) incl.
projecting parts and control.
Mass: Approx. 281.4 g (9.93 oz) incl. batteries / excl. accessories
Supplied accessories:
Mount with wheel sensor (1), Thick/Thin rubber pads (2 each),
Wheel magnet (1), Zip ties (5), Double-sided tape (1), Screws (2)
Design and specifications are subject to change without notice.

2
ICF-M88B
TABLE OF CONTENTS
1. SERVICING NOTES ............................................... 2
2. GENERAL ................................................................... 3
3. DISASSEMBLY
3-1. Disassembly Flow ........................................................... 4
3-2. Cabinet (Lower) Block .................................................... 4
3-3. Chassis Assy .................................................................... 5
3-4. MAIN Board.................................................................... 5
4. TEST MODE.............................................................. 7
5. ELECTRICAL ADJUSTMENTS ......................... 8
6. DIAGRAMS
6-1. Printed Wiring Boards – TUNER Section –................... 10
6-2. Schematic Diagram – TUNER Section – ....................... 11
6-3. Printed Wiring Board
– PANEL/POWER SUPPLY Section – ........................... 12
6-4. Schematic Diagram
– PANEL/POWER SUPPLY Section – ........................... 13
7. EXPLODED VIEWS
7-1. Cabinet (Upper) Section .................................................. 16
7-2. Chassis Section................................................................ 17
7-3. Cabinet (Lower) Section.................................................. 18
8. ELECTRICAL PARTS LIST................................ 19
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.
SECTION 1
SERVICING NOTES
UNLEADED SOLDER
Boards requiring use of unleaded solder are printed with the lead-
free mark (LF) indicating the solder contains no lead.
(Caution: Some printed circuit boards may not come printed with
the lead free mark due to their particular size)
: LEAD FREE MARK
Unleaded solder has the following characteristics.
•Unleaded solder melts at a temperature about 40 ˚C higher
than ordinary solder.
Ordinary soldering irons can be used but the iron tip has to be
applied to the solder joint for a slightly longer time.
Soldering irons using a temperature regulator should be set to
about 350 ˚C.
Caution: The printed pattern (copper foil) may peel away if
the heated tip is applied for too long, so be careful!
•Strong viscosity
Unleaded solder is more viscou-s (sticky, less prone to flow)
than ordinary solder so use caution not to let solder bridges
occur such as on IC pins, etc.
•Usable with ordinary solder
It is best to use only unleaded solder but unleaded solder may
also be added to ordinary solder.

3
ICF-M88B
SECTION 2
GENERAL This section is extracted from
instruction manual.
Location of Controls
R
A
D
I
O
P
O
W
E
R
L
I
G
H
T
E
N
T
E
R
/
S
E
L
E
C
T
T
U
N
E
M
O
D
E
B
A
N
D
/
S
E
T
V
O
L
B
A
N
D
/
S
E
T
T
U
N
E
M
O
D
E
RADIO POWER
LIGHT
VOL
E
N
T
E
R
/
S
E
L
E
C
T
MP H
AM
PM
FM
FREEZE
PRESET
MHz
MP H
kHz
km/h inc h
AM
km/h
mile
CLOCK ODO DIST RT AVG MAX
mm
RADIO P OWER LIGHT ENTER/S ELECT TUNE MODE BAND/SET
VOL*
FM antennaFM SENS
DX/LOCAL
Jog lever
*The re is a tactile dot beside VOL to show the direction to turn up
the volume.
Setting the Clock
The clock time display of this unit is a 12-hour system.
When the batteries are first installed, AM 12:00 flashes and CLOCK turns on
in the display.
1Press RADIO POWER to turn off the power.
2Press MODE/FREEZE repeatedly until CLOCK appears.
3Hold down ENTER/SELECT for more than 2 seconds until
AM 12 starts flashing.
4Push the Jog lever towards +or –to adjust the hour, then press
ENTER/SELECT.
The beep sounds and the minute setting starts to flash.
If you hold down the Jog lever towards +or —, the digit changes rapidly.
Midnight is indicated as AM 12:00 and Noon is indicated by PM 12:00.
g
5 Repeat step 4above to adjust the minutes.
: starts flashing and the clock starts operating.
To set the current time exactly to the second, adjust the minute setting and
then press ENTER/S ELECT to synchronize it with a time signal (such as
the telephone time signal).
Note
If you do not push the Jog lever towards +or —, or ENTER/S ELECT within
about 65 seconds, the clock setting mode will be canceled.

ICF-M88B
4
•This set can be disassembled in the order shown below.
3-1. DISASSEMBLY FLOW
SECTION 3
DISASSEMBLY
Note: Follow the disassembly procedure in the numerical order given.
3-2. CABINET (LOWER) BLOCK
1 Slide the hook (battery case lid)
in the direction of arrow,
and open the battery case lid.
battery case lid
2 screw (P1.7 × 10)
4
5 Remove two solders.
3 four screws
(P1.7
× 10)
6 cabinet (lower) block
3-2. CABINET (LOWER) BLOCK
(Page 4)
3-3. CHASSIS ASSY
(Page 5)
3-4. MAIN BOARD
(Page 5)
SET

ICF-M88B
5
3-4. MAIN BOARD
3-3. CHASSIS ASSY
1 Remove five solders.
4 screw
5 chassis assy
3 button assy
1 Remove two solders.
2 two hooks
3 screw
4 MAIN board
1 Remove the solder.
1 Remove two solders.
2 hook

ICF-M88B
6
POSITION OF LEAD WIRES
three ditches
two ditches
boss
boss
lead wire (battery terminal (+))
cabinet (lower) block
lead wire (red)
lead wire (gray)
lead wire (red)
lead wire (gray)
DX/LOCAL board
lead wire (black)

7
ICF-M88B
TP117
(KR3)
TP115
(KS1)
TP116
(KS0)
IC101
– KEY BOARD (Conductor Side) –
SECTION 4
TEST MODE
EEPROM INITIALIZE MODE
Procedure:
1. Turn on the power to place the set in the standby state.
2. Press the [BAND/SET], [LIGHT] and [MODE/FREEZE] keys
simultaneously for 5 seconds, or short the TP116 (KS0) and
TP117 (KR3) on the key board.
3. When the EEPROM initialize mode is activated, the BEEP
1is outputted and “dEL” is displayed on the LCD for one
second.
4. After one second elapsed, the BEEP 2is outputted, and the
EEPROM initialize mode is deactivated and the set returns to
the standby state.
LCD AND KEY TEST MODE
Procedure:
1. Turn on the power to place the set in the standby state.
2. Short the TP115 (KS1) and TP117 (KR3) on the key board.
3. When the LCD and key test mode is activated, the BEEP 1is
outputted and the LCD becomes all lit state.
4. Each time a key is pressed, the segment assigned to each key
turns off (see below). Also, if the [LIGHT] key is pressed, the
LCD back light turns on. (It turns off at the release of LCD
and ket test mode)
5. When all keys were pressed, the BEEP 2is outputted, and
the LCD and key test mode is deactivated and the set returns
to the standby state.
Note 1:The pulse input is ignored during each test mode.
Note 2:In the event that theVDET1 terminal (pin rl of IC101) on the key
boarddetects“L” duringeach testmode,the test mode isdeactivated
and the set returns to the standby state.
Note 3:The amplifierpower turns onby the mainclock operation to prepare
for the BEEP output during each test mode.
Key Segment Display
POWER S0, S2, S4 below LCD display-1
TUNE MODE S6, S8, S10 below LCD display-2
BAND/SET S12, S14, S16 below LCD display-3
+S18, S20, S22 below LCD display-4
–S3, S5, S7 below LCD display-5
RESET S9, S11, S13 below LCD display-6
MODE/FREEZE S15, S17, S19 below LCD display-7
ENTER/SELECT S21, S23, S25 below LCD display-8
LIGHT S1, S24 below LCD display-9
MPH
AM
PM
FM
FREEZE
PRESET
MHz
MPH
kHz
km/h inch
AM
km/h
mile
CLOCK ODO DIST RT AVG MAX
mm
LCD display
MPH
kHz
km/h inch
LCD display-1
mile
RT AVG MAX
LCD display-2
AM
PM
CLOCK ODO
LCD display-3
DIST
LCD display-4
MPH
FM
AM
km/h
mm
LCD display-5
FREEZE
LCD display-6
PRESET
MHz
LCD display-7
LCD display-8
LCD display-9
Connecting Location:

8
ICF-M88B
AM IF ADJUSTMENT
Adjust for a maximum reading on level meter
T1 450 kHz
AM VCO VOLTAGE ADJUSTMENT
Adjustment Part Frequency Display Reading on Digital Voltmeter
L1 530 kHz 1.2 ±0.1 V
Confirmation 1,710 kHz 7.2 ±0.5 V
AM TRACKING ADJUSTMENT
Adjust for a maximum reading on level meter
ANT1 590 kHz
CT1 1,490 kHz
FM VCO VOLTAGE ADJUSTMENT
Adjustment Part Frequency Display Reading on Digital Voltmeter
Confirmation 108.0 MHz 8.9 ±1.0 V
Confirmation 87.5 MHz 2.3 ±0.5 V
FM TRACKING ADJUSTMENT
Adjust for a maximum reading on level meter
L2 87.5 MHz
CT2 108.0 MHz
Adjustment Location: MAIN board (See page 9)
0 dB=1 µV
[AM]
Setting:
Function: RADIO
BAND: AM
[FM]
Setting:
Function: RADIO
BAND: FM
•Repeat the procedures in each adjustment several times, and
the trackingadjustmentsshould be finallydone by thetrimmer
capacitors.
•Remove FM antenna in FM adjustment.
AM RF signal
generator
30% amplitude
modulation by
400 Hz signal
Output level:
as low as possible
Put the lead-wire
antenna close to
the set.
+
–
level mete
r
set
8 Ω
MAIN board
TP15 (AF GND)
MAIN board
TP12 (SP OUT)
FM RF signal
generator
22.5 kHz frequency
deviation by 400 Hz
signal
Output level:
as low as possible
+
–
level mete
r
MAIN board
TP15 (AF GND)
MAIN board
TP12 (SP OUT)
set
8 Ω
0.01 µ F
MAIN board
TP10 (RF GND)
MAIN board
TP13 (FM IN)
digital voltmete
r
TP9 (VT)
TP8 (GND)
100 k
Ω
MAIN board
SECTION 5
ELECTRICAL ADJUSTMENTS

ICF-M88B
99
Adjustment Location:
T1
AM IF Adjustment
L1
AM VCO Voltage Adjustment
FM Tracking Adjustment
CT2
L2
AM Tracking Adjustment
CT1
ANT1
– MAIN BOARD (Component Side) –
– MAIN BOARD (Conductor Side) –
IC1
TP15
(AF GND)
TP10
(RF GND) TP13 (FM IN)
TP9
(VT)
TP12
(SP OUT)
TP8
(GND)
IC2

ICF-M88B
1010
SECTION 6
DIAGRAMS
•Note for PrintedWiring Boards and Schematic Diagrams
Note on PrintedWiring Boards:
•X: parts extracted from the component side.
•Y: parts extracted from the conductor side.
•W: indicates side identified with part number.
•z: Through hole.
•f: internal component.
•: Pattern from the side which enables seeing.
•: Carbon pattern.
(The other layers' patterns are not indicated.)
Caution:
Pattern face side: Parts onthe patternface sideseen from
(Conductor Side) the pattern face are indicated.
Parts face side: Parts on the parts face side seen from
(Component Side) the parts face are indicated.
Note on Schematic Diagram:
•All capacitors are in µF unless otherwise noted. (p: pF)
50 WV or less are not indicated except for electrolytics
and tantalums.
•All resistors are in Ωand 1/4W or less unless otherwise
specified.
•f: internal component.
•C: panel designation.
•A: B+ Line.
•H: adjustment for repair.
•Power voltage is dc 3V and fed with regulated dc power
supply from battery terminal.
•Voltages and waveforms are dc with respect to ground
under no-signal (detuned) conditions.
no mark : FM/AM
•Voltagesare taken withaVOM (Inputimpedance 10 MΩ).
Voltage variations may be noted due to normal produc-
tion tolerances.
•Waveforms are taken with a oscilloscope.
Voltage variations may be noted due to normal produc-
tion tolerances.
•Circled numbers refer to waveforms.
•Signal path.
F: FM
f: AM
6-1. PRINTED WIRING BOARDS –TUNER Section – :Uses unleaded solder.
R21
R17
C36R19
C40C38
R3
C9
R24
JC4
JC9
R5
C12
C28
R11
R20
C44C45
C2
R2
C3
C6
C14
R13
C4
R7
JC12 JC11 JC10
C35
C8
R25
C11
JC3
C32
C30
C26
R9
R10
R4
C10
C39 C37
C42 C43
R1
C47 C46
L4
D1
IC2
IC1
D2
KA
D3
KA
Q3
BCE
C16
C20
C23
C24
JC5
R6
R14
C15
C29
C19
C13
R8
R12
JC8
R23
JC6
ECB
ECB
Q2
Q1
D4
X1
1
1
3
8
JW1 JW2 JW3
C22
C34
+
+
C31
+
CT1
L1
L1
JW7
JW6
JW4
JW8 CF3
L3
L2
CT2
C27
BPF1
+
T1
CF1 CF2
C21
C17
+
+
+
C18
C25
+
RV1
MAIN BOARD
(11)
11
1-862-330-
TP8
(GND)
TP12
(SP OUT)
TP9
(VT)
TP15
(AF GND)
TP13
(FM IN)
TP10 (RF GND)
1
1
10
20
11
2
K
A
A
SP1
GRAY RED RED NATURAL BLK
ANT1
AM FERRITE-ROD
ANTENNA
1
14
1
15
28 3
54
13
54
VOL
A
A
K
KEY BOARD
A
RED
GRY
RED
BLK
GRY
RED
BLK
GRY
RED
GRAY
GRAY
RED
L301
R302
S301
DX/LOCAL BOARD
(11)
11
1-862-331-
ANT2
FM LEAD-WIRE
ANTENNA
FM SENS
LOCAL DX
A
B
C
D
E
1 2 3 4 5 6
•Semiconductor
Location
Ref. No. Location
D1 D-5
D2 C-4
D3 D-4
D4 C-1
IC1 C-3
IC2 C-5
Q1 C-2
Q2 B-2
Q3 D-4
(Page 12)