Sony SRS-T77 - Travel Speakers With Worldwide Voltage AC... User manual

SERVICE MANUAL
Amplifier section
• Power output: 2 W + 2 W
• Input: Speaker cord with stereo miniplug (50 cm)
• Input impedance: 4.7 kilohms (at 1 kHz)
Speaker section
• System: Full-range, bass reflex type
• Speaker units: Magnetically shielded ø 39 mm
• Impedance: 8 ohms
• Rated input power: 2 W
• Maximum input power: 4 W
General
• Power requirement: Four R6 (size AA) batteries/DC 9 V
• Battery life (at TOTAL 10 mW output):
Approx. 24 hours Sony alkaline batteries LR6 (SG)
Approx. 8 hours Sony manganese batteries R6P (SR)
• Dimensions: Approx. 221 ×127 ×117 mm (8
3
/ 4 ×5 ×
4
5
/ 8 in.) (w/h/d) (during use)
Approx. 143 ×127 ×29 mm (5
3
/ 4 ×5 ×1
3
/ 16 in.)
(w/h/d) (folded)
• Mass: Approx. 260 g (9 oz.) not incl. batteries Approx.
350 g (12 oz.) incl. batteries
• Supplied accessories: AC power adaptor
AC- E90A (1), Carrying case (1), Plug adaptor (1)*
*For world model only.
Design and specifications are subject to change without
notice.
Features
•The Sony SRS-T77 is a compact (CD case-sized) speaker
system with a built-in power amplifier. This system can be
connected to a Discman, WALKMAN*, headphone
stereo, etc.
•The SRS-T77 has a dual power supply system. When you
operate the SRS-T77 outdoors, use battery power, and
when you operate it indoors, use an AC power adaptor
(supplied).
Rich and powerful bass
•Power output of 2 W + 2 W
•The embedded MEGA BASS delivers rich bass regardless
of the sound volume.
*WALKMAN is a registered trademark of Sony
Corporation.
Note on the AC power adaptor
Use only the AC-E90A (supplied) AC power adaptor.
Do not use any other AC power adaptor.
Polarity of the plug
ACTIVE SPEAKER SYSTEM
US Model
Canadian Model
Tourist Model
SRS-T77
Ver 1.0 2001.02
9-927-993-11 Sony Corporation
2001B0500-1 Audio Entertainment Group
C2001.2 General Engineering Dept.
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.
SPECIFICATIONS

2
SRS-T77 SECTION 1
GENERAL This section is extracted from
instruction manual.
• LOCATION OF CONTROL
Right speaker
Left speaker POWER switch
Speaker cord
Stand
Bass reflex duct
POWER indicator

3
SRS-T77
2-2. CASE, FRONT
• This set can be disassembled in the order shown below.
2-1. DISASSEMBLY FLOW
SECTION 2
DISASSEMBLY
Note: Follow the disassembly procedure in the numerical order given.
Set Speaker unit (SP1) (L ch)/(SP2) (R ch)
AMP board, Jack board
Draw Around LeadWires
Case, Front
3 six screws
(P2.6
× 10)
4 screw
(P2
× 5)
1 Open stand
in the direction of arrow
A .
2 lid, battery case
5 case, front
A

4
SRS-T77
2-3. SPEAKER UNIT (SP1) (L ch)/(SP2) (R ch)
1 Remove two solders of lead
from speaker unit (SP1) (L ch).
6 Remove two solders of lead
from speaker unit (SP2) (R ch).
2 two screws
(P2.6
× 6)
7 two screws
(P2.6
× 6)
4 Remove “holder, rotary shaft”
in the direction of arrow
A .
A
9
Remove “holder, rotary shaft”
in the direction of arrow
B .
8
B
3
5 speaker unit (L ch) assy
0 speaker unit (R ch) assy
Note: It is not necessary to remove speaker unit (L ch) assy
to remove speaker unit (R ch) assy.
qf four screws
(P2.6
× 6)
w; four screws
(P2.6
× 6)
qj four screws
(P2.6
× 6)
qa four screws
(P2.6
× 6)
qs cabinet (L), rear
qk cabinet (R), rear
qh cabinet (L) assy, front
ws cabinet (R) assy, front
qg speaker unit (SP1) (L ch)
wa speaker unit (SP2) (R ch)
qd absorbent, acoustic
ql absorbent, acoustic
Note: It is not necessary to remove speaker unit (SP1) (L ch)
to remove speaker unit (SP2) (R ch).

SRS-T77
55
SECTION 3
DIAGRAMS
3-1. BLOCK DIAGRAM2-4. AMP BOARD, JACK BOARD
2-5. DRAW AROUND LEAD WIRES
2 two screws
(P2
× 5)
3 AMP board
S1
knob, switch
1 Remove four solders of lead
from speaker unit (SP1/SP2).
1 Remove two solders of lead (yellow, brown)
from jack board and solder of lead (red)
from “spring, plug battery”.
4 Remove two solders of lead (yellow, brown)
from AMP board and solder of lead (black)
from “spring, minus battery”.
4 Remove solder
of lead.
6 jack board
1 Remove three solders of cord (with plug).
1 Remove solder of lead.
5 two screws
(P2
× 5)
Note 3: When installation AMP board,
fit switch (S1) and “knob, switch”.
Note 1: When installation leads and assembling set,
refer to DRAW AROUND LEADWIRE.
Note 2: It is not necessary to remove AMP board
to remove jack board.
–+
Note 1: It is possible that lead wire are caught between the “case, front”and “case, rear”and cut.
Draw around lead wires as shown in the figure.
Note 2: Put the knot of the cord (with plug)
in the groove of“case, rear”.
lead wire
(speaker unit (SP2) (R ch)
-AMP board)
lead wire
(speaker unit (SP1) (L ch)
-AMP board)
lead wire (red)
(AMP board-“spring, plus battery”)
lead wire (yellow)
(AMP board-jack board)
lead wire (blown)
(AMP board-jack board)
lead wire (black)
(jack board-“spring, minus battery”)
cord (with plug)
“case, rear”
lead wire
(AMP board condenser (C22) minus side
-jack board)
jack board
AMP board
red natural color
natural color
natural color
red
green
green
•SIGNAL PATH
: LINE INPUT
S1 (1/4)
S1 (2/4)
S1 (3/4)
S1 (4/4)
B+
SP1
(L-CH)
SP2
(R-CH)
P1
(LINE INPUT)
POWER AMP
IC1
OUT1
IN1+ POWER
AMP 1912
OUT2
IN2+ POWER
AMP
MUTING
Q1
MUTING
Q2
29
POWER AMP
IC2
OUT1
IN1+ POWER
AMP 19
12
OUT2IN2+ POWER
AMP 29
+ +
JK1
DC IN 9V
!
DRY BATTERY
SIZE “AA”
(IEC DESIGNATION R6)
4PCS. 6V
D2
POWER
S1
POWER
OFF/DIRECT
ON
LIMITER
Q3

SRS-T77
66
SP1
(L-CH)
+–
AMP BOARD (CONDUCTOR SIDE)
1-680-334-
(11)
11
-1 -2
-3 -4
S1
POWER
OFF/
DIRECT ON
t
SP2
(R-CH)
P1
(LINE INPUT)
+–
C22
+
GRN RED NATURAL
RED
YEL
BRN
DRY BATTRY
SIZE “AA”
(IEC DESIGNATION R6)
4PCS. 6V
BCE
Q1
BCE
Q2
C15 +C4 +
C14 +C6 +C13 +C5 +
C7 +
C9 +
C8 +
C3 +
C16 +
C17 +
C12 +
C10 +
C11 +
D2
D1
D3
R13 R14
R18
R17
R16
R15
R11
C103
C1
R7 R9 R3 R5
R1
C24 C101
R19
C20
C18
R20
C25
C23
C21
C19
R2
C102
R4 C104
R12 R10
R8 R6
C2
C26
IC2 IC1
AMP BOARD (COMPONENT SIDE)
(11)
11
1-680-334-
A
K
A
K
POWER 20
11
1
10 11 10
20 1
R21 R22
JACK BOARD
(COMPONENT SIDE)
(11)
11
1-680-335-
JACK BOARD
(CONDUCTOR SIDE)
(11)
11
1-680-335-
Q3 JK1
DC IN 9V
–+
BLK
YEL
BRN
A
B
C
D
E
1234 5678
3-2. PRINTED WIRING BOARDS
Note on Printed Wiring Boards:
•X: parts extracted from the component side.
•Y: parts extracted from the conductor side.
•z:Through hole.
•: Pattern from the side which enables seeing.
(The other layers' patterns are not indicated.)
Caution:
Pattern face side: Partsonthe pattern facesideseenfrom
(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.
•Semiconductor
Location
Ref. No. Location
D1 A-1
D2 B-1
D3 B-1
IC1 B-5
IC2 B-3
Q1 A-3
Q2 A-2
Q3 D-7

SRS-T77
77
3-3. SCHEMATIC DIAGRAM
Note on Schematic Diagram:
•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.
•C: panel designation.
•IC Block Diagram
IC1, 2 TEA2025D-013TR
20 19 18 17 16 15 14 11
+
–
13 12
+
–
THERMAL
PROTECT
START
CIRCUIT
10987654321
DECOUPLING
VCC OUT 1 BOOT 1 GND GND GND GND FEEDBACK IN1 (+) GND (SUB
)
BRIDGE
OUT 2
BOOT 2
GND GND GND GND
FEEDBACK
IN2 (+)
SVR
•A: B+ Line.
•Power voltage is dc 9V and fed with regulated dc power
supply from external power voltage jack.
•Voltages are dc with respect to ground under no-signal
conditions.
no mark : POWER ON
•VoltagesaretakenwithaVOM(Input impedance 10 MΩ).
Voltage variations may be noted due to normal produc-
tion tolerances.
•Signal path.
F: LINE INPUT

SRS-T77
88
AMP JACK
SECTION 4
EXPLODED VIEW
1 4-223-349-11 CASE, FRONT
*2 A-4542-669-A AMP BOARD, COMPLETE
3 4-223-357-01 HOLDER, ROTARY SHAFT
4 3-042-545-01 SHEET, BLIND
6 X-3379-828-1 CABINET (L) ASSY, FRONT
7 3-042-547-01 ABSORBENT, ACOUSTIC
8 4-223-355-11 CABINET (L), REAR
9 4-223-348-01 KNOB, SWITCH
10 4-223-361-01 SPRING, BATTERY RELAY
11 4-223-350-11 CASE, REAR
12 4-223-359-01 SPRING, PLUS BATTERY
13 4-223-360-01 SPRING, MINUS BATTERY
14 4-223-358-01 STAND
15 3-042-546-01 CUSHION, BATTERY CASE LID
16 4-223-362-11 LID, BATTERY CASE
17 4-223-356-11 CABINET (R), REAR
18 X-3379-829-1 CABINET (R) ASSY, FRONT
19 4-224-447-01 SPRING, STAND
*20 1-680-335-11 JACK BOARD
21 1-559-891-81 CORD (WITH PLUG)
SP1 1-529-859-11 SPEAKER (Lch)
SP2 1-529-859-11 SPEAKER (Rch)
Ref. No. Part No. Description Remark Ref. No. Part No. Description Remark
1
2
20
not supplied
#1
#1
#4
#2
#2
#2
#3
#1
#3
#3
#3
#2
not supplied
not supplied
not supplied
not supplied
SP1
not supplied
not supplied
21
18
SP2
B
A
A
B
14
12
13
11
15
16
7
10
9
7
8
3
4
43
419
6
17
• Items marked “*” are not stocked since they
are seldom required for routine service. Some
delay should be anticipated when ordering
these items.
• The mechanical parts with no reference num-
ber in the exploded views are not supplied.
• Accessories and packing materials are given
in the last of the electrical parts list.
NOTE:
• -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
SECTION 5
ELECTRICAL PARTS LIST
NOTE:
• Due to standardization, replacements in the
parts list may be different from the parts speci-
fied 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 order-
ing 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
*A-4542-669-A AMP BOARD, COMPLETE
********************
< CAPACITOR >
C1 1-165-112-11 CERAMIC CHIP 0.33uF 20% 10V
C2 1-165-112-11 CERAMIC CHIP 0.33uF 20% 10V
C3 1-126-187-11 ELECT CHIP 0.1uF 20% 50V
C4 1-126-187-11 ELECT CHIP 0.1uF 20% 50V
C5 1-128-397-21 ELECT CHIP 100uF 20% 16V
C6 1-128-397-21 ELECT CHIP 100uF 20% 16V
C7 1-126-209-11 ELECT CHIP 100uF 20% 4V
C8 1-126-209-11 ELECT CHIP 100uF 20% 4V
C9 1-128-397-21 ELECT CHIP 100uF 20% 16V
C10 1-128-397-21 ELECT CHIP 100uF 20% 16V
C11 1-126-209-11 ELECT CHIP 100uF 20% 4V
C12 1-126-209-11 ELECT CHIP 100uF 20% 4V
C13 1-128-397-21 ELECT CHIP 100uF 20% 16V
C14 1-128-397-21 ELECT CHIP 100uF 20% 16V
C15 1-126-393-11 ELECT CHIP 33uF 20% 10V
C16 1-124-779-00 ELECT CHIP 10uF 20% 16V
C17 1-124-779-00 ELECT CHIP 10uF 20% 16V
C18 1-125-837-11 CERAMIC CHIP 1uF 10% 6.3V
C19 1-125-837-11 CERAMIC CHIP 1uF 10% 6.3V
C20 1-125-837-11 CERAMIC CHIP 1uF 10% 6.3V
C21 1-125-837-11 CERAMIC CHIP 1uF 10% 6.3V
C22 1-126-935-11 CAP, ELECT 470uF 20% 16V
C23 1-162-970-11 CERAMIC CHIP 0.01uF 10% 25V
C24 1-165-176-11 CERAMIC CHIP 0.047uF 10% 16V
C25 1-165-176-11 CERAMIC CHIP 0.047uF 10% 16V
C26 1-162-964-11 CERAMIC CHIP 0.001uF 10% 50V
C101 1-162-964-11 CERAMIC CHIP 0.001uF 10% 50V
C102 1-162-964-11 CERAMIC CHIP 0.001uF 10% 50V
C103 1-162-965-11 CERAMIC CHIP 0.0015uF 10% 50V
C104 1-162-965-11 CERAMIC CHIP 0.0015uF 10% 50V
< DIODE >
D1 8-719-800-76 DIODE 1SS226
D2 8-719-812-43 LED TLG124A (POWER)
D3 8-719-105-57 DIODE RD3.9M-B1
< IC >
IC1 8-759-524-84 IC TEA2025D-013TR
IC2 8-759-524-84 IC TEA2025D-013TR
< TRANSISTOR >
Q1 8-729-230-49 TRANSISTOR 2SC2712-YG
Q2 8-729-230-49 TRANSISTOR 2SC2712-YG
< RESISTOR >
R1 1-216-829-11 METAL CHIP 4.7K 5% 1/16W
R2 1-216-829-11 METAL CHIP 4.7K 5% 1/16W
R3 1-216-814-11 METAL CHIP 270 5% 1/16W
R4 1-216-814-11 METAL CHIP 270 5% 1/16W
R5 1-216-821-11 METAL CHIP 1K 5% 1/16W
R6 1-216-821-11 METAL CHIP 1K 5% 1/16W
R7 1-216-823-11 METAL CHIP 1.5K 5% 1/16W
R8 1-216-823-11 METAL CHIP 1.5K 5% 1/16W
R9 1-216-813-11 METAL CHIP 220 5% 1/16W
R10 1-216-813-11 METAL CHIP 220 5% 1/16W
R11 1-216-833-11 METAL CHIP 10K 5% 1/16W
R12 1-216-833-11 METAL CHIP 10K 5% 1/16W
R13 1-216-833-11 METAL CHIP 10K 5% 1/16W
R14 1-216-821-11 METAL CHIP 1K 5% 1/16W
R15 1-216-821-11 METAL CHIP 1K 5% 1/16W
R16 1-216-821-11 METAL CHIP 1K 5% 1/16W
R17 1-216-789-11 METAL CHIP 2.2 5% 1/16W
R18 1-216-789-11 METAL CHIP 2.2 5% 1/16W
R19 1-216-823-11 METAL CHIP 1.5K 5% 1/16W
R20 1-216-823-11 METAL CHIP 1.5K 5% 1/16W
< SWITCH >
S1 1-554-295-21 SWITCH, SLIDE (POWER)
**************************************************************
*1-680-335-11 JACK BOARD
***********
< JACK >
JK1 1-569-966-21 JACK,DC (POLARITY UNIFIED TYPE)
(DC IN 9V)
< TRANSISTOR >
Q3 8-729-035-81 TRANSISTOR 2SB1436-QR
< RESISTOR >
R21 1-216-825-11 METAL CHIP 2.2K 5% 1/16W
R22 1-216-832-11 METAL CHIP 8.2K 5% 1/16W
**************************************************************
Les composants identifiés par une
marque 0sont critiquens pour la
sécurité.
Ne les remplacer que par une pièce
portant le numéro spécifié.
The components identified by
mark 0or dotted line with mark
0are critical for safety.
Replace only with part number
specified.
When indicating parts by reference
number, please include the board.

Ref. No. Part No. Description Remark Ref. No. Part No. Description Remark
9
SRS-T77
MISCELLANEOUS
**************
21 1-559-891-81 CORD (WITH PLUG)
SP1 1-529-859-11 SPEAKER (Lch)
SP2 1-529-859-11 SPEAKER (Rch)
************************************************************
**************
HARDWARE LIST
**************
#1 7-685-103-19 SCREW +P 2X5 TYPE2 NON-SLIT
#2 7-685-133-19 SCREW +P 2.6X6 TYPE2 SLIT
#3 7-685-135-19 SCREW +P 2.6X10 TYPE2 SLIT
#4 7-621-255-40 SCREW +P 2X6
************************************************************
ACCESSORIES & PACKING MATERIALS
*******************************
01-476-220-11 ADAPTOR, AC (Tourist)
01-476-658-11 ADAPTOR, AC (US, Canadian)
01-569-007-11 ADAPTOR, CONVERSION 2P (Tourist)
3-045-440-01 POUCH, CARRYING
3-224-730-11 MANUAL, INSTRUCTION (ENGLISH, FRENCH,
SPANISH)
The components identified by
mark 0or dotted line with
mark 0are critical for safety.
Replace only with part num-
ber specified.
Les composants identifiés par une
marque 0sont critiques pour la
sécurité.
Ne les remplacer que par une pièce
portant le numéro spécifié.

SRS-T77
REVISION HISTORY
Clicking the version allows you to jump to the revised page.
Also, clicking the version at the upper right on the revised page allows you to jump to the next revised
page.
Ver. Date Description of Revision
1.0 2001.02 New