T
ONE INPUT :
L
T
ONE DETECTION
CIRCUIT
LCD CONTRAST
LCD DRIVER
LCD DRIVER
LCD DRIVER
2.8V
2.7V
2.5V
LCD
KEY SWITCH
CONTR
OL
NO
T
ONE :
H
4BIT MICR
OCOMPUTER
21
21
C74
0.1
R92
1M
Ω
X3
4MHZ
Q23
AG
R84
10K
D12
IC8
3
2
1
R85
10K
R86
10K
R88
33K
C71
0.047
C72
0.047
IC8
5
6
7
R83
100K
R89
22K
R90
18K
C73
25V4.7
µ
R91
10K
AG
R87
100K
-5V
R109
3.3K
Q29
R108
10K
R107
100K
R103
100K
Q28
R106
18K
Q27
Q30
R105
4.7K
R102
4.7K
R104
4.7K
R101
4.7K
IC8
4
8
+5V(V2)
SW7
SW6
SW5
SW4
SW2
SW3
SW64
SW11
SW12
SW10
SW14
SW15
SW13
SW9
SW21
SW18
SW23
SW20
SW17
SW19
SW22
SW26
SW29
SW31
SW30
SW25
SW27
SW28
SW35
SW38
SW34
SW36
SW33
SW39
SW37
SW43
SW46
SW45
SW47
SW41
SW42
SW44
SW49
R93
22K
R94
22K
R95
22K
R96
22K
R100 22K
R99 22K
R97 22K
R98 22K
D3
D4
D5
D10
D9
D8
D7
D6
50V10
µ
C88
R110
22K
64
RD1
63
RD0
62
RB21
61
RB11
60
RB01
59
VCC
58
SEL
57
RA1
56
RA0
55
R93
54
R92
53
R91
52
R90
51
R83
50
R82
49
R81
48
R80
47
R73
46
R72
45
R71
44
R70
43
R63
42
R62
41
R61
40
R60
39
R43
38
R42
37
R41
36
R40
35
R31
34
R32
33
R33
17
D11
18
D12
19
D13
20
R0
21
R01
22
R02
23
R03
24
R10
25
R11
26
R12
27
R13
28
R20
29
R21
30
R22
31
R23
32
R30
1
RE0
2
TEST
3
OSC1
4
OSC2
5
RESET
6
X1
7
X2
8
GND
9
D0
10
D1
11
D2
12
D3
13
D4
14
D5
15
D9
16
D10
R131
33
R132
33
C115
0.1
C62
0.1
AG
SW40
SW24
SW32
SW8
SW48
SW16
+5V(V2)
+5V(V2)
+5V(V1)
+5V(V1)
+5V(V1)
+5V(V1)
+5V(V1)
R114
0
SW50
7
SW54
CN201
2
31
C204
0.1
µ
SW59
22
SW53
19
+5V
6
SW52
C201
0.1
µ
15
SW61
MA0
4
MA1
3
MA2
2
MA3
1
MA4
60
MA5
59
MA6
58
MA7
57
MA8
56
MA9
55
MA10
54
MA11
53
MD0
37
MD1
36
MD2
35
MD3
34
MD4
33
MD5
32
MD6
31
MD7
30
RD0
45
RD1
44
RD2
43
RD3
42
RD4
41
RD5
40
RD6
39
RD7
38
MA12
52
MA13
51
MA14
50
MA15
49
DB0
28
DB1
27
DB2
26
DB3
25
CS
15
RES
14
RS
18
DB4
24
DB5
23
DB6
22
DB7
21
R/W
17
E
16
CP0
9
SYC
12
MA
19
D2
18
VDD
29
GND
20
D1
47
CL2
46
MB
5
FLM
10
CL1
11
R
7
C
6
CR
8
WE
13
SW51
30
28
SW56
D201
SW63
IC206
2
V1
3
V2
6
V3
7
V4
5
VIN3
8GND
4
VIN2
1
VCC
21
SW57
14
R202
39K
10
SW58
9
+5V
+5V
16
27
+5V
SW62
C206
0.1
µ
C203
0.1
µ
32
24
+5V
IC202
2
A0
3
A1
4
A2
14
GND
5
A3
6
A4
7
A5
8
A6
9
A7
22
OE
27
WE
28
VCC
10
A8
21
A9
23
A10
24
A11
11
I/O1
12
I/O2
13
I/O3
15
I/O4
16
I/O5
17
I/O6
18
I/O7
19
I/O8
26
CE2
25
A12
20
CE1
11
13
C205
0.1
µ
25
20
3
17
23
+5V
R201
10
Ω
18
26
12
1
29
8
+5V
SW60
C202
15P
SW55
+5V
4
R203
39K
C70
V1
92
O63
63
O62
62
O61
61
O60
60
O59
59
O57
57
O56
56
O55
55
O54
54
O53
53
O51
51
O50
50
O49
49
O48
48
O47
47
O45
45
O44
44
O43
43
O42
42
O41
41
O39
39
O38
38
O37
37
O36
36
O35
35
O33
33
O32
32
O31
31
O30
30
O29
29
O27
27
O26
26
O25
25
O24
24
O23
23
O21
21
O20
20
O19
19
O18
18
O17
17
O15
15
O14
14
O13
13
O12
12
O11
11
O9
9
O8
8
O7
7
O6
6
O5
5
O3
3
O2
2
O1
1
V3
89
V4
88
VDD
91
VDD
90
D13
96
D12
95
D11
94
P/S
85
VSS
86
VEE
87
SDI
97
LO
AD
98
M
93
CP
100
CDI
99
DISP_OFF
84
V1
92
O63
63
O62
62
O61
61
O59
59
O58
58
O57
57
O56
56
O55
55
O53
53
O52
52
O51
51
O50
50
O49
49
O47
47
O46
46
O45
45
O44
44
O43
43
O41
41
O40
40
O39
39
O38
38
O37
37
O35
35
O34
34
O33
33
O32
32
O31
31
O29
29
O28
28
O27
27
O26
26
O25
25
O23
23
O22
22
O21
21
O20
20
O19
19
O17
17
O16
16
O15
15
O14
14
O13
13
O11
11
O10
10
O9
9
O8
8
O7
7
O5
5
O4
4
O3
3
O2
2
O1
1
V3
89
V4
88
VDD
91
VDD
90
D13
96
D12
95
D11
94
P/S
85
VSS
86
VEE
87
SDI
97
LO
AD
98
M
93
CP
100
O79
79
O77
77
O76
76
O75
75
O74
74
O73
73
O71
71
O70
70
O69
69
O68
68
O67
67
O65
65
O64
64
O80
80
CD0
82
CD1
99
DISP_OFF
84
V1
30
O48
8
O46
6
O45
5
O44
4
O43
3
O42
2
O40
80
O39
79
O38
78
O37
77
O36
76
O34
74
O33
73
O32
72
O31
71
O30
70
O29
69
O27
67
O26
66
O25
65
O24
64
O22
62
O21
61
O20
60
O19
59
O18
58
O16
56
O15
55
O14
54
O13
53
O12
52
O10
50
O9
49
O8
48
O7
47
O6
46
O4
44
O3
43
O2
42
O1
41
V5
28
VDD
32
VSS
34
VEE
27
M
36
CP
38
O5
45
O11
51
O17
57
O23
63
O28
68
O35
75
O41
1
O47
7
V2
29
DIO1
40
RS/LS
33
DISP_OFF
31
C200
0.1
µ
D20
D13
D15
D19
D14
D16
D18
R139
10K
R140
10K
27
29
13
12
11
7
5
16
3
34
18
8
6
CN2
2
21
33
14
22
25
10
28
20
30
31
4
15
26
19
17
35
32
1
24
9
36
23
D17
R204
1K
SW1
1
2
4
3
+5V
R205
470
D202
INT[1]
R[12]
R[13]
R[20]
R[21]
R[22]
R[23]
INT[1-2],IOR,IO
W
,R[12-13],R[20-23]
D[5],D[9-12],R[1-3]
R[3]
R[2]
R[1]
D[12]
D[11]
D[10]
D[5]
D[2],R[30-33],R[60-63],R[70-73]
R[30]
RR[70-73],RR[80-83]
RB[1],RB[11],RB[21],RD[0],R[90-93]
D[2]
D[9]
INT[2]
R[33]
R[32]
R[31]
R[60]
R[61]
R[62]
R[63]
R[73]
R[72]
R[71]
RR[80]
RR[81]
RR[82]
RR[83]
D[2],R[30-33],R[60-63],R[70-73]
R[60]
R[61]
R[62]
R[63]
R[30]
R[31]
R[32]
R[33]
R[70]
R[71]
R[72]
R[73]
D[2]
RR[70-73],RR[80-83]
RR[70]
RR[71]
RR[72]
RR[73]
RR[80]
RR[81]
RR[82]
RR[83]
RD[0]
R[90]
RD[0]
RB[21]
RB[11]
RB[1]
R[93]
R[92]
R[91]
R[90]
IO
W
IOR
RB[21]
RD[0]
R[93]
RB[11]
RB[1]
R[91]
R[92]
RR[73]
RR[70]
RR[71]
RR[72]
R[70]
RR[83]
RR[82]
RR[81]
RR[80]
RR[73]
RR[72]
RR[71]
RR[70]
CO7
CO6
CO5
CO2
CO1
CO4
CO3
CO15
CO9
CO12
CO13
CO11
CO10
CO14
CO21
CO20
CO17
CO22
CO19
CO23
CO18
CONF
REDIAL
TRANS
FWD
PR
OG
INT
P
A
USE
1
56
34
SP
2
78
#
9*
0
AU
T
O
TEL
TYPE0
TEL
TYPE1
RD[1]
MUTE
CO8
CO16
CO24
FLASH
HOLD
MW
FR1
FR2
FR5
MENU1
MENU2
MENU3
FR3
FR4
SHIFT
FL2
FL4
FL1
2AP:PSUP1179Z
FL5
FL3
(1)
(3)
(2)
(4) (5)
(6)
(7) (8)
Summary of Contents for KX-T7456 - Digital 24 Button Speakerphone Display
Page 4: ...4 DISASSEMBLY INSTRUCTIONS 4 1 HOW TO REMOVE THE LOWER CABINET Procedure 1 4 ...
Page 8: ...5 IC DATA 5 1 IC1 8 ...
Page 11: ...11 ...
Page 15: ...15 ...
Page 20: ...7 4 DATA COMMUNICATION CIRCUIT 1 Function 20 ...
Page 24: ...The reset signal is negledted 24 ...
Page 29: ...8 TROUBLESHOOTING GUIDE 8 1 NO OPERATION 8 2 THE LCD DOES NOT OPERATE 29 ...
Page 31: ...8 5 SPEAKER PHONE TROUBLE 8 6 TONE DIAL TROUBLE 8 7 TROUBLE OF OHCA 31 ...
Page 32: ...8 8 HANDSET TROUBLE 9 TERMINAL GUIDE OF ICS TRANSISTORS AND DIODES 32 ...
Page 36: ...12 CABINET AND ELECTRICAL PARTS LOCATION 13 ACCESSORIES AND PACKING MATERIALS 36 ...
Page 49: ...33 37 34 35 36 25 32 ...
Page 55: ...SW301 CN301 1 2 3 ...
Page 57: ...1 5 2 6 3 7 4 8 ...
Page 58: ...9 13 10 14 11 15 12 16 ...
Page 59: ...17 21 18 22 19 23 20 24 ...
