Panasonic KX-AT7730RU Service Manual ▷ View online
21
KX-AT7730 Series
8 Disassembly and Assembly Instructions
1. Remove the Stand.
2. Remove 5 Screws A.
3. Remove the Lower Cabinet.
3. Remove the Lower Cabinet.
4. Remove the Cable from the Main Board.
5. Remove the LCD Holder from the Main Board.
5. Remove the LCD Holder from the Main Board.
Stand
A
A
A
A
A
Lower Cabinet
Main Board
LCD Holder
Cable
22
KX-AT7730 Series
Caution
6. Remove 5 Screws A.
7. Remove the Main Board from the Upper Cabinet.
7. Remove the Main Board from the Upper Cabinet.
A
A
A
A
A
Upper Cabinet
Main Board
Make attention direction of mic ass'y, push MIC RUBBER
certainly down to the bottom.
certainly down to the bottom.
Process MIC lead wire straight in the dashed area.
Pass PCB/LED lead wire between boss and rib.
Don't put lead wire over LCD HOLDER.
23
KX-AT7730 Series
9 Maintenance
9.1.
How To Replace a Flat Package IC
Even if you do not have the special tools (for example, a spot heater) to remove the Flat IC, with some solder (large amount), a
soldering iron and a cutter knife, you can easily remove the ICs that have more than 100 pins.
soldering iron and a cutter knife, you can easily remove the ICs that have more than 100 pins.
9.1.1.
Preparation
• PbF (: Pb free) Solder
• Soldering Iron
• Soldering Iron
Tip Temperature of 700°F ± 20°F (370°C ± 10°C)
Note: We recommend a 30 to 40 Watt soldering iron. An
expert may be able to use a 60 to 80 Watt iron where
someone with less experience could overheat and damage
the PCB foil.
Note: We recommend a 30 to 40 Watt soldering iron. An
expert may be able to use a 60 to 80 Watt iron where
someone with less experience could overheat and damage
the PCB foil.
• Flux
Recommended Flux: Specific Gravity
→ 0.82.
Type
→ RMA (lower residue, non-cleaning type)
Note: See About Lead Free Solder (PbF: Pb free) (P.4).
9.1.2.
Removal Procedure
1. Put plenty of solder on the IC pins so that the pins can be
completely covered.
Note:
Note:
If the IC pins are not soldered enough, you may give
pressure to the P.C. board when cutting the pins with
a cutter.
pressure to the P.C. board when cutting the pins with
a cutter.
2. Make a few cuts into the joint (between the IC and its
pins) first and then cut off the pins thoroughly.
3. While the solder melts, remove it together with the IC
pins.
When you attach a new IC to the board, remove all solder
left on the land with some tools like a soldering wire. If some
solder is left at the joint on the board, the new IC will not be
attached properly.
left on the land with some tools like a soldering wire. If some
solder is left at the joint on the board, the new IC will not be
attached properly.
9.1.3.
Procedure
1. Tack the flat pack IC to the PCB by temporarily soldering
two diagonally opposite pins in the correct positions on
the PCB.
the PCB.
Be certain each pin is located over the correct pad on the PCB.
2. Apply flux to all of the pins on the IC.
3. Being careful to not unsolder the tack points, slide the
soldering iron along the tips of the pins while feeding
enough solder to the tip so that it flows under the pins as
they are heated.
enough solder to the tip so that it flows under the pins as
they are heated.
9.1.4.
Removing Solder From Between
Pins
Pins
1. Add a small amount of solder to the bridged pins.
2. With a hot iron, use a sweeping motion along the flat part
2. With a hot iron, use a sweeping motion along the flat part
of the pin to draw the solder from between the adjacent
pads.
pads.
24
KX-AT7730 Series
10 Schematic Diagram
10.1. for KX-AT7730X, XB / KX-AT7730SX, SXB
GR
GR
GR
GR
GR
GR
GR
GR
GR
GR
GR
GR
C
E
B
A
D
F
3
6
4
2
5
8
7
11
10
9
G
H
12
K0
K6
K5
K4
K3
K2
K1
K5
K4
K3
K2
K1
C0
C1
C2
C3
C5
C4
L7
L6
L5
L4
L3
L2
L1
L0
L0
L1
L2
L3
L4
L5
L6
L7
C3
C2
C1
C0
K0
K1
K2
K3
K4
K6
K5
C4
C5
D6
D9
Q101
Q109
1
B1
2
E
3
B2
4
C2
5
C1
Q11
1
B1
2
E
3
B2
4
C2
5
C1
Q12
1
B1
2
E
3
B2
4
C2
5
C1
Q15
1
B1
2
E
3
B2
4
C2
5
C1
Q16
1
B1
2
E
3
B2
4
C2
5
C1
Q105
1
Tr1_B
2
E
3
Tr2_B
5
Tr1_C
4
Tr2_C
Q106
1
Tr1_B
2
E
3
Tr2_B
5
Tr1_C
4
Tr2_C
Q107
1
Tr1_B
2
E
3
Tr2_B
5
Tr1_C
4
Tr2_C
Q108
1
Tr1_B
2
E
3
Tr2_B
5
Tr1_C
4
Tr2_C
IC7
3
OUT
2
GND
1
VCC
IC5
1
I/O1
2
O/I1
12
CONT4
13
CONT1
3
O/I2
14
VDD
4
I/O2
11
I/O4
5
CONT2
10
O/I4
6
CONT3
9
O/I3
7
VSS
8
I/O3
D10
D3
D30
D31
D
32
D33
D34
D4
D5
D7
C8
0.22u
C103
2.2u
C113
2.2u
C112
2.2u
C114
2.2u
C115
2.2u
C116
2.2u
C50
2.2u
C51
2.2u
C131 0.1u
C21
0.1u
C24
0.1u
C26
0.1u
C27
0.1u
C32
0.1u
C34
0.1u
C41
0.1u
C42
0.1u
C48
0.1u
C59
0.1u
C61
0.1u
C64
0.1u
C81
0.1u
16
C91
0.1u
C60
0.022u
C47
0.033u
C49
0.033u
C14
0.047u
C44
0.047u
C45
0.047u
C46
0.047u
C62
0.047u
C93
0.047u
C208
1000p
C212
1000p
C213
1000p
C6
1000p
C101
0.01u
C22
0.01u
C29
0.01u
C66
0.01u
C67
0.01u
C84
0.01u
C12
0.015u
C23
0.015u
C33
0.015u
C209
2200p
C28
2200p
C130
330p
C7
820p
C30
220u
6.3
T2
1
2
4
56
7
10
9
8
X1
20M
1
2
3
CN1
1
VSS => GND
2
RS => A0
3
CSB => CS
4
SI => SI
5
SCL => SCL
6
VDD => VDD
7
VSS => NC
8
V4 => NC
9
V3 => VG
10
V2 => V0
11
V1 => XV0
12
V0 => VSS
13
ResetB => RES
14
VSS => GND
R106
1
k
R108
1k
R206
1k
R240
1k
R31
1k
R129
10k
R231 10k
R81
10k
R91
10k
R93
10k
R97
10k
R99
10k
R1
100k
R289
100k
R30
100k
R52
100k
R58
100k
R73
100k
R96
100k
R23
120
R59
12k
R68
120k
R76
120k
R140
15
R36
150
R60
1.5k
R82
1.5k
R126
15k
R156
15k
R98
15k
R55
150k
R14
18
R37
18k
R42
18k
R54
18k
R92
18k
R9
20k
R101 220
R102 220
R131
220
R133
220
R135
220
R12
2.2k
R123
2.2k
R201
2.2k
R57
2.2k
R2
22k
R208
22k
R67
220k
R86
220k
R48
2.2M
R10
2.7k
R103
2.7k
R128
2.7k
R21
2.7k
R7
27k
R70
27k
R238
270k
R24
270k
R51
2.7M
R234
30k
R49
30k
R22
3.3k
R45
3.3k
R127
33k
R230
33k
R80
33k
R84
330k
R233
39k
R32
39k
R79
39k
R5
47
R237
470
R107
4.7k
R26
4.7k
R41
4.7k
R44
4.7k
R78
47k
R125
470k
R13
470k
R25
470k
R29
470k
R43
470k
R95
470k
R236
5.1k
R132
56
R134
56
R16
56
R27
5.6k
R46
5.6k
R47
5.6k
R74
5.6k
R69
56k
R105
68
R6
680
R15
6.8k
R87
6.8k
R4
68k
R50
68k
R75
68k
R77
8.2k
R56
3.3
D18
3
4
1
2
D19
3
4
1
2
D20
3
4
1
2
D21
3
4
1
2
D22
3
4
1
2
D23
3
4
1
2
D24
3
4
1
2
D25
3
4
1
2
D26
3
4
1
2
D27
3
4
1
2
D28
3
4
1
2
D29
3
4
1
2
D17
D16
D15
D14
D13
D11
R136
56
IC1
17
P3_5
18
P3_4
19
P3_3/*INT3
20
P2_7
21
P2_6
22
P2_5
23
P2_4
24
P2_3
25
P2_2
26
P2_1
27
P2_0
28
P3_6
29
P3_1
30
P8_6
31
P8_5
32
P8_4
33
P8_3
34
P8_2
35
P8_1
36
P8_0
37
P6_7
38
P6_6/TXD2
39
P6_5/CLK2
40
P4_5
41
P1_7
42
P1_6
43
P1_5
44
P1_4
45
P1_3
46
P1_2
47
P1_1
48
P1_0
49
P0_7/DA1
50
P0_6/DA0
51
P0_5
52
T_CONT1
53
P0_3
54
P0_2
55
P0_1
56
P0_0
57
P6_4
58
P6_3
59
P6_2
60
P6_1
61
P6_0
62
P5_7
63
P5_6
64
P3_2
1
P3_0
2
P4_2/VREF
3
MODE
4
HS_MUTE
5
P4_4/XCOUT
6
*RESET
7
P4_7/XOUT
8
VSS/AVSS
9
P4_6/XIN
10
VCC/AVCC
11
P5_4
12
P5_3
13
P5_2
14
P5_1
15
P5_0
16
P3_7
AG
AG
AG
AG
AG
R104
N
C
DG
D3.3V
D3.3V
D3.3V
A5V
DG
D3.3V
DG
DG
D3.3V
+6V
D5V
D3.3V
DG
DG
D3.3V
DG
D5V
DG
DG
A5V
C5
NC
C13
NC
AG
AG
AG
C10
NC
AG
+6V
C43
NC
AG
AG
AG
AG
AG
AG
R235
NC
C133
NC
AG
AG
AG
AG
AG
AG
C207
NC
AG
R19
NC
R20
NC
AG
AG1
AG
AG
C214
N
C
D3.3V
AG
G
A
G
A
AG
C68
NC
AG
AG
AG
+6V
AG
AG
AG
+6V
AG
C82
NC
AG
D3.3V
DG
D3.3V
D3.3V
DG
D3.3V
DG
R121
NC
DG
DG
D3.3V
R154
NC
NC
R155
DG
DG
AG
AG
D3.3V
R88
2.7k
AG
R89
68k
R124
0
D3.3V
AG
R85
NC
AG
AG
A5V
D3.3V
DG
R153
N
C
AG
DG
R8
33
AG
D3.3V
AG
D3.3V
R38
6.8k
AG
R296
NC
R144
470
R90
470
AG
AG1
JK2
1
2
3
4
5
JK3
1
2
5
3
4
C211
0.01u
DG
AG
AG
DG
DG2
D3.3V
DG
+6V
D5V
V1
H
T
R
L
B8
B1
B2
B3
B4
B5
B6
B7
A1
A3
A5
A7
A8
A9
A2
A4
A6
E4
E3
E1
E2
E5
E6
M3
AG2
SP+
SPN
K1
N5
N6
N7
N8
SP1
SP2
M2
M1
AG1
K2
N1
N2
N3
N4
AG
CN9
NC
1
2
3
4
CN2-1
MICP
CN2-2
MICN
CN3-1
SPP
CN3-2
SPN
CN4-2
CN4-1
CN5-1
CN5-2
C57
1000u
10
AG
SW42
HOLD
SW52
HOOK
SW16
1
SW22
2
SW28
3
SW34
4
SW40
5
SW46
6
SW15
7
SW21
8
SW27
9
SW33
*
SW39
0
SW45
#
SW41
REDIAL
SW47
<
SW43
SP-PHONE
SW48
>
SW49
V
SW50
SW11
CO12
SW12
CO11
SW13
CO10
SW14
CO9
SW17
CO8
SW18
CO7
SW19
CO6
SW20
CO5
SW23
CO4
SW24
CO3
SW25
CO2
SW26
CO1
SW29
CONF
SW30
FWD/DND
SW31
MUTE
SW32
STORE
SW35
M.W
SW36
PAUSE
SW37
FLASH
SW38
TRANSFER
SW44
ICM
SW51
PROGRAM
J4
J1
R28
3.3k
R34
3.3k
AG
AG
G1
G2
JK1
1
2
3
4
5
CN7-6
CN8-1
CN8-5
CN7-7
CN7-3
CN8-2
CN8-3
CN8-6
CN8-4
CN8-7
CN7-5
CN7-4
CN7-1
CN7-2
T1
16
3
4
2
R66
N
C
C71
NC
R62
NC
C73
NC
C72
N
C
R64
N
C
R65
N
C
C74
NC
R63
NC
C75
NC
R207
NC
C76
NC
AG
AG
AG
AG
AG
Q6
Q10
Q13
Q14
Q21
Q22
AG
A5V
IC10
1
AOUT
2
A-IN
3
A+IN
4
GND
5
B+IN
6
B-IN
7
BOUT
8
V+
IC6
1
AOUT
2
A-IN
3
A+IN
4
GND
5
B+IN
6
B-IN
7
BOUT
8
V+
IC9
1
NC
2
A
4
Y
5
VCC
3
GND
R300
NC
D3.3V
R301
NC
R302
NC
R303
NC
IC11
1
CE
2
GND
3
VOUT
4
VDD
C205
220u
10
Q111
Q112
Q113
Q114
DG
DG
DG
IC2
4
VSS
1
OUT
2
VDD
3
NC
IC4
N
C
1
CD
2
+VREF
6
V+
7
GND
3
+VIN
8
VOUT2
4
-VIN
5
VOUT1
J2
NC
J3
NC
R61
0
R17
0
C102
NC
Q5
Q3
Q4
Q8
Q9
Q102
Q18
Q20
DG
Q110
( )
NC
C94
1000p
R94
4.7k
R100
68k
C104
0.01u
C106 0.01u
C107
0.1u
C108
0.1u
C110
0.1u
C117
0.01u
C132
1u
C204
0.1u
C210
0.01u
C3
22u
16
C35
1u
C36
0.1u
C53
47u
6.3
C54
100u
6.3
C63
100u
6.3
C85
0.01u
C86
0.01u
C92
1u
C95
0.1u
C96
0.01u
D1
4
1
3
2
D2
4
1
3
2
PC1
1
2
3
4
Q1
Q2
R3
2.2k
C203
47u
25
RA2
1.2k
1
2
3
45
6
7
8
D12
D40
R232
15k
R71
10k
R72
3.9k
R39
8.2k
R40
6.8k
R139
33
R137
100
R138
56
IC3
1
RR
2
RTX
3
TXI
4
TXO
5
TLI
23
XDC
24
VLC
25
ACF
26
RXO
27
RXI
6
TLO
7
RLI
8
RLO
9
MCI
10
MCO
12
CP2
13
XDI
14
SKG
18
*CS
19
SKI
20
VCC
21
VB
22
GND
15
SKO
16
V+
17
AGC
11
CP1
28
RRX
R157
0
SW1
4
C
1
2
3
5
6
IC8
1
IN/OUT
2
OUT/IN
3
GND
5
VCC
4
CONT
R158
0
R159
N
C
C118
NC
C250
100p
L1
L2
L3
C251
220p
AG
C252
220p
C253
220p
AG
C254
220p
AG
C255
220p
C65
220p
L4
L7
NC
L6
NC
C25
10u
C31
10u
C4
2.2u
C52
10u
C55
10u
C58
4.7u
C2
10u
10
C215
100u
6.3
C9
100u
10
C206
100u
10
L5
D41
NC
C56
220u
10
Split PCB 1
Split PCB 2
CN8
C
N7
Split PCB 1
CN2
CN3
CN4
CN5
CN8
C
N7
R157 0 => NC
R158 0 => NC
R159 NC => 0
C112 2.2uF => NC
C113 2.2uF => 1uF
C114 2.2uF => NC
C115 2.2uF => NC
C118 NC => 1uF
LCD Driver Old => New
1
KX-A
T7730X, XB / KX-A
T7730SX, SXB MAIN BOARD
C
8
R1
2
R1
0
2.7
k
R
Q
2
7
C
4
C6
3
3
1
1
5
L
4
2
6
1
9
L
3
C2
22
C2
22
C5
5
10
C5C5
88
4747
u
2
3
SS
N
3
4
2
3
SS
6
B
-I
N
B
7
OU
T
Q
3
Q
3
25
5
100
3
49
R
24
T/IT/I
NN
/I
1
2
1
I/O
1
1
8
C6
1
A
G
1
1
5
4
N
M
1
Q
5
7k
C
2
.2
u
9
1
0
OOO
4
8
0.1
3
R4
1
C4
1
77
u
C4C4
44
0000
66
5656
R4R4
4
3
3
2
On using the speakerphone
2.4V
Ringer
Signal
SP-Phone
Reception Signal
SP-Phone
T
ransmission
Signal
2.8V
1.5V
2.7V
2.0V
2.1V
2.1V
1.5V
2.2V
2.8V
2.8V
2.8V
2.7V
2.8V
2.9V
2.5V
2.7V
2.8V
0
2.8V
5.4V
2.8V
0
0
0
0
6.1V
2.9V
2.8V
4.6V
22
u
1
Handset
T
ransmission
Signal
1.6V
1.7V
Handset
Reception Signal
6
C
3
6
C
3
1.5V
22
u
22
u
8
O
3
O/
9
01
u
R
NC
27
DTMF
Signal
for Dial
0
0
0
3.3V
3.3V
3.3V
3.3V
0.8V
3.3V
3.3V
3.3V
3.3V
3.3V
0
4.0MHz
0
3.3V
5.4V
6.1V
12V
5.3V
20V
1.8V
1.6V
1.8V
3.3V :
0V :
The handset is in use
The speakerphone is in use
0
0
0
0
0
0
0
0
0
3.3V
3.3V
3.3V
3.3V
3.3V
3.3V
3.3V
3.3V
3.3V
3.3V
3.3V
0
0
0
3.3V
3.3V
3.3V
3.3V
3.3V
3.3V
0
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