Somy IT-B2 User manual

1
SERVICE MANUAL
SPECIFICATIONS
Dial signal Tone, 10 PPS (pulse) selectable
Dimensions Approx. 152 ×71 ×216 mm (w/h/d)
(Approx. 6 ×2 7/8 ×8 5/8 inches)
Mass Approx. 560 g
(Approx. 1 lb 4 oz)
Supplied accessories Telephone line cords (2)
Wall bracket (1)
Screws (2) (attached inside the wall bracket)
Directory label (1 sheet)
Design and specifications are subject to change without notice.
IT-B2
Mexican Model
TELEPHONE
MICROFILM
Notes on Chip Component Replacement
•Never reuse a disconnected chip component.
•Notice that the minus side of a tantalum capacitor may be dam-
aged by heat.

2
SECTION 1
GENERAL This section is extracted
from instruction manual.

33
SECTION 2
DISASSEMBLY
Note : Follow the disassembly procedure in the numerical order given.
2-1. CABINET (LOWER)
2-2. MAIN BOARD
3 Open the cabinet (lower).
2 BTP 3X10
1 BTP 3X10
1 BTP 2X6
4 BTP 2.6X8
6 MAIN board
5 BTP 2.6X8
2 buzzer
3 modular jack
(J201)
2-3. KEY BOARD
1 BTP 2.6X8
3 KEY board
4 rubber key switch
5 button (12 key)
2 BTP 2.6X8

44
IT-B2
3-1. PRINTED WIRING BOARDS
SECTION 3
DIAGRAMS
D101 B-2
D102 B-2
D103 B-2
D104 B-2
D105 A-3
D106 A-3
D107 A-3
D108 A-3
D109 B-6
D202 C-2
D205 C-5
D206 C-5
D207 D-5
IC101 A-4
IC201 D-2
Q201 C-1
Q202 C-1
Q204 E-4
Q205 C-4
Q206 B-4
Q207 E-4
Q208 C-4
ZD101 B-3
ZD201 C-2
ZD202 D-5
• Semiconductor
Location
Ref. No. Location
Note:
•X: parts extracted from the component side.
•: Carbon pattern.
•¢: internal component.
•b: Pattern from the side which enables seeing.

55
IT-B2
3-2. SCHEMATIC DIAGRAM • Refer to page 6 for IC Block Diagrams.
Note:
• All capacitors are in µF unless otherwise noted. pF: µµF
50 WV or less are not indicated except for electrolytics
and tantalums.
• All resistors are in Ωand 1/4W or less unless otherwise
specified.
•¢: internal component.
•C: panel designation.
•U: B+ Line.
• Power voltage is dc 12V and fed with regulated dc power
supply from J101 with 100 Ωin series.
• Voltage is dc with respect to ground under no-signal
condition.
no mark : OFF HOOK
( ) : ON HOOK
• Voltages aretakenwith aVOM(Input impedance10MΩ).
Voltage variations may be noted due to normal produc-
tion tolerances.
• Signal path.
N: RX (fromTEL LINE)
O:TX (to TEL LINE)
P: bell

66
• IC Block Diagrams
IC101 DBL5002
IC201 HM91652B
1
2
3
4
8
7
6
5
REGULATOR
WITH
HYSTERESIS
VCC
RSL
LFI
LFO
OUT
HFI
HFO
GND
AMP
LOW FREQ
OSC HIGH FREQ
OSC
22
COLUMN
INTERFACE
CIRCUIT
OSC
DIVIDER
LNB
MEMORY
KERNEL CONTROL CIRCUIT
HDO
21
R4
20
R3
19
R2
18
R1
17
MODE
16
DTMF
15
PO
14
HKS
13
VDD
12
HFO
1
HDI
2
C1
3
C2
4
C3
5
C4
7
OSC IN
8
OSD OUT
9
MUTE
10
VSS
11
HFI
6
C5
VDD
VDD
ROW/COLUMN
PROGRAMMING
COUNTER
OUTPUT
INTERFACE
CIRCUIT
INPUT
INTERFACE
CIRCUIT
ROW
INTERFACE
CIRCUIT
SAVE
MEMORY MEMORY
DECODER &
DATA LATCH
PULSE
GENERATOR D/A CONVERTER
SECTION 4
EXPLODED VIEW
NOTE:
• The mechanical parts with no reference
number in the exploded views are not supplied.
• Items marked “*” are not stocked since
they are seldom required for routine service.
Some delay should be anticipated
when ordering these items.
• -XX and -X mean standardized parts, so
they may have some difference from the
original one.
• Color Indication of Appearance Parts
Example :
KNOB, BALANCE (WHITE) ... (RED)
Parts Color Cabinet’s Color
Ref. No. Part No. Description Remark
N
N
Ref. No. Part No. Description Remark
• Accessories and packing materials are
given in the last of this parts list.
3
11
1
1
12 12
2
2
13 5
7
15
9
SP101
J201
SW101
2
2
10
4
14
8
6
1 3-925-103-01 FOOT, RUBBER
2 7-685-533-19 SCREW +BTP 2.6X6 TYPE2 N-S
3 X-3371-275-1 HANDSET ASSY, LOCAL
*4 A-3672-801-A MAIN BOARD, COMPLETE
5 1-762-340-11 SWITCH, RUBBER KEY
6 4-908-618-21 SCREW (+BTP) (2X6)
7 3-925-097-01 CABINET (UPPER)
8 3-925-098-01 CABINET (LOWER)
9 3-925-099-01 BUTTON (12 KEY)
10 3-925-100-01 LEVER (HOOK)
11 3-925-101-01 HANGER (HANDSET)
12 7-685-547-11 SCREW +BTP 3X10 TYPE2 N-S
*13 1-660-943-11 KEY BOARD
14 1-769-626-11 WIRE (FLAT TYPE) (9 CORE)
15 1-696-455-11 CORD, CURL
J201 1-770-504-11 JACK, MODULAR (4C) 4P (HANDSET)
SP101 1-529-116-11 BUZZER, PIEZOELECTRIC
SW101 1-692-494-11 SWITCH, HOOK (HOOK)

7
SECTION 5
ELECTRICAL PARTS LIST
NOTE:
• Due to standardization, replacements in
the parts list may be different from the
parts specified in the diagrams or the
components used on the set.
• -XX and -X mean standardized parts, so
they may have some difference from the
original one.
• RESISTORS
All resistors are in ohms.
METAL:Metal-film resistor.
METAL OXIDE: Metal oxide-film resistor.
F:nonflammable
• Items marked “*” are not stocked since
they are seldom required for routine service.
Some delay should be anticipated
when ordering these items.
• SEMICONDUCTORS
In each case, u : µ, for example:
uA.. : µA.. uPA.. : µPA..
uPB.. : µPB.. uPC.. : µPC.. uPD.. : µPD..
• CAPACITORS
uF : µF
• COILS
uH : µH
Ref. No. Part No. Description Remark Ref. No. Part No. Description Remark
When indicating parts by reference
number, please include the board.
KEY MAIN
*1-660-943-11 KEY BOARD
**********
< CONNECTOR >
*CN101B 1-569-704-11 HOLDER, CABLE (PC BOARD) 9P
*************************************************************
*A-3672-801-A MAIN BOARD, COMPLETE
*********************
1-769-626-11 WIRE (FLAT TYPE) (9 CORE)
< CAPACITOR >
C101 1-137-479-11 FILM 1uF 5% 400V
C102 1-126-964-11 ELECT 10uF 20% 50V
C103 1-126-959-11 ELECT 0.47uF 20% 50V
C104 1-163-215-00 CERAMIC CHIP 0.0027uF 10% 50V
C201 1-128-551-11 ELECT 22uF 20% 25V
C203 1-163-038-00 CERAMIC CHIP 0.1uF 25V
C204 1-126-933-11 ELECT 100uF 20% 16V
C205 1-163-038-00 CERAMIC CHIP 0.1uF 25V
C206 1-163-205-00 CERAMIC CHIP 0.001uF 5% 50V
C207 1-163-205-00 CERAMIC CHIP 0.001uF 5% 50V
C208 1-163-205-00 CERAMIC CHIP 0.001uF 5% 50V
C209 1-163-205-00 CERAMIC CHIP 0.001uF 5% 50V
C210 1-163-205-00 CERAMIC CHIP 0.001uF 5% 50V
C211 1-163-205-00 CERAMIC CHIP 0.001uF 5% 50V
C212 1-163-205-00 CERAMIC CHIP 0.001uF 5% 50V
C213 1-163-205-00 CERAMIC CHIP 0.001uF 5% 50V
C215 1-126-959-11 ELECT 0.47uF 20% 50V
C216 1-163-021-11 CERAMIC CHIP 0.01uF 10% 50V
C217 1-163-021-11 CERAMIC CHIP 0.01uF 10% 50V
C218 1-163-021-11 CERAMIC CHIP 0.01uF 10% 50V
C220 1-126-796-11 ELECT 22uF 20% 25V
C222 1-126-176-11 ELECT 220uF 20% 10V
C223 1-163-055-00 CERAMIC CHIP 0.0047uF 10% 50V
C224 1-163-038-00 CERAMIC CHIP 0.1uF 25V
C225 1-115-871-11 ELECT 1uF 20% 50V
C226 1-163-213-00 CERAMIC CHIP 0.0022uF 5% 50V
C227 1-163-021-11 CERAMIC CHIP 0.01uF 10% 50V
C228 1-163-213-00 CERAMIC CHIP 0.0022uF 5% 50V
C230 1-163-063-00 CERAMIC CHIP 0.022uF 50V
C240 1-163-063-00 CERAMIC CHIP 0.022uF 50V
C250 1-163-205-00 CERAMIC CHIP 0.001uF 5% 50V
C251 1-163-063-00 CERAMIC CHIP 0.022uF 50V
C252 1-161-039-00 CERAMIC 0.001uF 10% 50V
C260 1-164-159-21 CERAMIC 0.1uF 50V
< CONNECTOR >
*CN101A 1-569-704-11 HOLDER, CABLE (PC BOARD) 9P
< DIODE >
D101 8-719-059-25 DIODE 1A6
D102 8-719-059-25 DIODE 1A6
D103 8-719-059-25 DIODE 1A6
D104 8-719-059-25 DIODE 1A6
D105 8-719-989-91 DIODE 1N4148A-T265
D106 8-719-989-91 DIODE 1N4148A-T265
D107 8-719-989-91 DIODE 1N4148A-T265
D108 8-719-989-91 DIODE 1N4148A-T265
D109 8-719-989-91 DIODE 1N4148A-T265
D202 1-808-100-11 DIODE MA700
D205 8-719-989-91 DIODE 1N4148A-T265
D206 8-719-989-91 DIODE 1N4148A-T265
D207 8-719-989-91 DIODE 1N4148A-T265
< FUSE >
F101 1-533-713-11 FUSE (500mA/250V)
< IC >
IC101 8-759-595-76 IC DBL5002
IC201 8-759-582-35 IC HM91652B
< JACK >
J101 1-766-250-21 JACK, MODULAR (2C) 6P (LINE)
< TRANSISTOR >
Q201 8-729-804-21 TRANSISTOR 2SA1319TP-S
Q202 8-729-803-98 TRANSISTOR 2SC3332TP-S
Q204 8-729-173-38 TRANSISTOR 2SA733TP-Q
Q205 8-729-173-38 TRANSISTOR 2SA733TP-Q
Q206 8-729-025-58 TRANSISTOR KSC2331Y
Q207 8-729-173-38 TRANSISTOR 2SA733TP-Q
Q208 8-729-119-76 TRANSISTOR 2SA733TP-P
< RESISTOR >
R101 1-249-421-11 CARBON 2.2K 5% 1/4W
R102 1-249-421-11 CARBON 2.2K 5% 1/4W

8
Sony Corporation
Digital Telecommunication Company
9-923-812-31 99G04034-1
Printed in Japan C1999. 7
Published by Mobile Electronics Company
Quality Assurance Dept.
IT-B2
MAIN
R103 1-216-071-00 METAL CHIP 8.2K 5% 1/10W
R104 1-216-101-00 METAL CHIP 150K 5% 1/10W
R105 1-218-763-11 RES,CHIP 300K 5% 1/10W
R106 1-216-049-11 RES,CHIP 1K 5% 1/10W
R107 1-216-073-00 METAL CHIP 10K 5% 1/10W
R108 1-216-097-00 RES,CHIP 100K 5% 1/10W
R201 1-259-882-11 CARBON 3.3M 5% 1/4W
R202 1-259-882-11 CARBON 3.3M 5% 1/4W
R203 1-216-113-00 METAL CHIP 470K 5% 1/10W
R204 1-216-033-00 METAL CHIP 220 5% 1/10W
R205 1-216-295-00 SHORT 0
R206 1-216-093-00 RES,CHIP 68K 5% 1/10W
R207 1-216-053-00 METAL CHIP 1.5K 5% 1/10W
R210 1-216-121-00 RES,CHIP 1M 5% 1/10W
R211 1-216-069-00 METAL CHIP 6.8K 5% 1/10W
R213 1-216-057-00 METAL CHIP 2.2K 5% 1/10W
R214 1-216-113-00 METAL CHIP 470K 5% 1/10W
R215 1-216-073-00 METAL CHIP 10K 5% 1/10W
R216 1-216-073-00 METAL CHIP 10K 5% 1/10W
R217 1-216-113-00 METAL CHIP 470K 5% 1/10W
R218 1-216-029-00 METAL CHIP 150 5% 1/10W
R219 1-216-059-00 METAL CHIP 2.7K 5% 1/10W
R220 1-216-049-11 RES,CHIP 1K 5% 1/10W
R221 1-216-065-00 RES,CHIP 4.7K 5% 1/10W
R222 1-216-071-00 METAL CHIP 8.2K 5% 1/10W
R223 1-216-053-00 METAL CHIP 1.5K 5% 1/10W
R224 1-249-400-11 CARBON 39 5% 1/4W
R225 1-249-400-11 CARBON 39 5% 1/4W
R226 1-249-400-11 CARBON 39 5% 1/4W
R227 1-249-400-11 CARBON 39 5% 1/4W
R228 1-216-057-00 METAL CHIP 2.2K 5% 1/10W
R229 1-216-113-00 METAL CHIP 470K 5% 1/10W
R230 1-216-001-00 METAL CHIP 10 5% 1/10W
R231 1-216-093-00 RES,CHIP 68K 5% 1/10W
R232 1-216-053-00 METAL CHIP 1.5K 5% 1/10W
R242 1-216-049-11 RES,CHIP 1K 5% 1/10W
R244 1-216-049-11 RES,CHIP 1K 5% 1/10W
R245 1-216-049-11 RES,CHIP 1K 5% 1/10W
R251 1-216-198-00 RES,CHIP 1K 5% 1/8W
R253 1-259-882-11 CARBON 3.3M 5% 1/4W
R261 1-216-017-00 RES,CHIP 47 5% 1/10W
R300 1-249-441-11 CARBON 100K 5% 1/4W
< VARISTOR >
SA101 1-801-271-11 VARISTOR (VF07M10820K)
< SWITCH >
SW101 1-692-494-11 SWITCH, HOOK (HOOK)
SW102 1-692-207-21 SWITCH, SLIDE (RINGER LEVEL)
SW201 1-572-903-51 SWITCH, SLIDE (DIAL MODE)
< VIBRATOR >
X201 1-579-673-11 VIBRATOR, CERAMIC (3.58MHz)
< DIODE >
ZD101 8-719-155-07 DIODE RD27EL2TN
ZD201 8-719-101-50 DIODE RD5.1EL2TN
ZD202 8-719-154-61 DIODE RD6.8EL2TN
*************************************************************
MISCELLANEOUS
***************
5 1-762-340-11 SWITCH, RUBBER KEY
15 1-696-455-11 CORD, CURL
J201 1-770-504-11 JACK, MODULAR (4C) 4P (HANDSET)
SP101 1-529-116-11 BUZZER, PIEZOELECTRIC
*************************************************************
ACCESSORIES & PACKING MATERIALS
********************************
1-696-453-11 CORD (WITH MODULAR PLUG) (LINE) (215cm)
1-696-454-11 CORD (WITH MODULAR PLUG) (LINE) (15cm)
3-378-839-01 LABEL (SCALE CARD)
3-798-915-14 MANUAL, INSTRUCTION (ENGLISH)
3-798-915-24 MANUAL, INSTRUCTION (SPANISH)
X-3370-607-1 CASE ASSY, WALL HOOK
Ref. No. Part No. Description Remark Ref. No. Part No. Description Remark