Panasonic KX-T7730CA Service Manual ▷ View online
21
KX-T7730CA
9 Miscellaneous
9.1.
Terminal Guide of ICs, Transistors and Diodes
22
KX-T7730CA
9.2.
How To Replace a Flat Package
IC
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 sol-
dering iron and a cutter knife, you can easily remove the ICs that have more than 100 pins.
dering iron and a cutter knife, you can easily remove the ICs that have more than 100 pins.
9.2.1.
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 some-
one with less experience could overheat and damage the
PCB foil.
expert may be able to use a 60 to 80 Watt iron where some-
one 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.3).
9.2.2.
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.
9.2.3.
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 sol-
dering 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.
solder to the tip so that it flows under the pins as they are
heated.
9.2.4.
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.
23
KX-T7730CA
9.3.
Memo
24
KX-T7730CA
10 Schematic Diagram
(1)
(2)
(3)
(4)
(6)
(8)
(9)
(10)
(11)
(12)
(14)
(16)
(17)
(18)
(19)
(20)
(13)
(15)
(5)
(7)
KX-T7730CA MAIN BOARD NO.1
R31
1K
R49 30K
R50 68K
R48 2.2M
R46
5.6K
R47
5.6K
R51 2.7M
C44
0.047
C45
0.047
C61
0.1
R56
3.3
+6V
R54
18K
R55
150K
R57 2.2K
C46
0.047
R42
18K
C42
0.1
R58
100K
C65
0.01
0.01
C59
0.1
C64
0.1
C58
Z4.7
C55
Z10
C51
Z2.2
Z2.2
C50
Z2.2
C27
0.1
R61
0
C62
0.047
R29
470K
R70 27K
R67 220K
R68 120K
AG
Q15
1
4
3
2
5
Q16
1
4
3
2
5 R69 56K
C48 0.1
C47
0.033
R45
3.3K
R52100K
R36
150
A5V
R38
10K
Q11
1
4
3 2
5
R134
39
D22
CO5
D26
CO9
D28
CO11
R131
270
D27
CO10
R132
39
R133
270
D23
CO6
D24
CO7
R135
270
R136
39
D20
CO3
D18
CO1
D19
CO2
D5V
SW26
CO1
SW46
6
SW40
5
SW22
2
SW34
4
SW23
CO4
SW12
CO11
SW14
CO9
SW33
*
SW27
9
SW25
CO2
SW15
7
SW28
3
SW21
8
SW18
CO7
SW11
CO12
SW17
CO8
SW45
#
SW24
CO3
SW20
CO5
SW19
CO6
SW39
0
SW16
1
D29
CO12
3
4
1
2
D25
CO8
D21
CO4
R138
220
R137
270
RA2
4.7K
4.7K
NC
C72
IC4 NC
1
CD
2
FC2
3
FC1
4
Vin
5
VO1
6
VCC
7
GND
8
VO2
NC
R62
NC
R65
NC
C71
NC
R64
R43
470K
NC
C73
IC5
11
10
12
IC5
2
1
13
NC
C74
NC
C75
NC
R66
R60
1.5K
R59
12K
R30
100K
C28
3300P
R37
27K
R53
47K
47K
NC R63
C31
Z10
CN2
1
+
2
-
CN3
1
+
2
-
R72
47K
R71
47K
D12
ICM
R139
39
NC
C43
DG
AG
AG
AG
AG
AG
AG
AG
AG AG AG
AG
NC
J2
NC
J3
IC5
3
4
5
AG
AG
D16
MUTE
D17
STORE
D14
CONF
D15
FWD/DND
D13
SP-PHONE
SW31
MUTE
SW30
FWD/DND
SW35
M.W
SW32
STORE
SW29
CONF
SW37
FLASH
SW36
PAUSE
SW47
SW48
SW44
ICM
SW41
REDIAL
SW38
TRANSFER
SW43
SP-PHONE
SW49
SW50
JK2
HANDSET JACK
3
SP
1
MIC
2
4
4
A1
A2
A3
A4
A5
A6
A7
A8
A9
B1
B2
B3
B4
B5
B6
B7
B8
E4
E3
E2
E1
E5
E6
G2
G1
AG
1
M3
AG2
SP- SP+
SW51
PROGRAM
SW1
3
4
2
1
2
1
SW13
CO10
CN6
1
2
2
R141
NC
CN4
1
2
CN5
1
2
2
R140
56
D11
M.W
AG
A5V
Q7
Q18
Q104
1
6
2
Q104
4
3
5
Q103
1
6
2
Q103
4
3
5
C84
0.01
R84
680K
R44
4.7K
C49
0.033
AG
R89
100K
Q12
1
4
3
2
5
A5V
R73
100K
SW52
HOOK
CN8
8
7
5
4
9
6
7
5
4
9
6
CN7
2
3
5
6
1
4
3
5
6
1
4
CN8
2
1
3
1
3
CN7
8
9
7
9
7
AG
AG
K2 K1
M1
SP1
M2
SP2
N3
N2
N4
N1
AG
NC
C76
R90
470
D31
D32
D33
D34
R206
1K
NC
R207
C29
2200P
R208
22K
R78
47K
R79
39K
AG
R86
270K
NC
R85
R88
3.9K
R87
10K
C66
0.01
C67
3300P
3300P
R80
47K
N5
N6
N7
N8
N6
N7
N8
AG
AG
IC3
1
RR
2
RTX
3
TXI
4
TXO
5
TLI
6
TLO
7
RLI
8
RLO
9
MCI
10
MCO
11
CP1
12
CP2
13
XDI
14
SKG
15
SKO
16
V+
17
AGC
18
CS
19
SKI
20
Vcc
21
VB
22
GND
23
XDC
24
VLC
25
ACF
26
RXO
27
RXI
28
RRX
C60
0.022
NC
C210
Q105
1
2
3
4
5
Q106
1
2
3
4
5
Q107
1
2
3
4
5
Q108
1
2
3
4
5
Q14
E
C
B
Q13
E
C
B
Q8
E
C
B
TP220
TP102
TP100
TP95
TP75
TP73
TP83
TP89
AG
C209
2200P
C211
0.01
C213
1000P
C214
NC
JK3
1
5
4
3
2
4
3
2
C30
6.3V220
C63
6.3V100
C57
6.3V1000
C54
6.3V100
6.3V100
C53 6.3V47
C56
6.3V220
C52
Z10
SP_RX_MUTE
SP_TX_MUTE
SP_TX_MUTE
HS_POWER
SP_POWER
SP_POWER
SP_VOL1
SP_VOL2
SP_VOL3
SP_VOL4
HS_VOL2
HS_VOL1
C[1]
C[0]
C[3]
C[2]
T_CONT3
T_CONT4
L[0]
L[1]
L[2]
L[3]
L[4]
L[5]
L[6]
L[7]
SP_POWER
SP_TX_MUTE
SP_RX_MUTE
T_CONT2
HS_POWER
K[0]
K[1]
K[2]
K[3]
K[4]
K[5]
C[4]
C[5]
K[7]
K[6]
HS_MUTE
RING_OFF
HEAD_SET
R
R
R
G
R
G
R
G
R
G
G
G
R
R
R
G
G
G
R
G
R
G
G
R
2.4V
2.8V
1.5V
2.7V
1.5V
2.7V
2.8V
5.4V
5.3V
2.0V
2.0V
0
0
2.8V
2.7V
2.5V
2.9V
2.8V
2.7V
2.8V
2.8V
2.8V
2.2V
1.5V
2.1V
2.1V
2.1V
0
0
0
2.8V
6.1V
2.9V
2.8V
4.6V
SP-Phone
Reception Signal
Reception Signal
SP-Phone
Transmission Signal
Transmission Signal
Ringer
Signal
Signal
5.4V :
0V :
The handset is in use
The speakerphone is in use
The speakerphone is in use
On using the speakerphone
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