![background image](http://html.mh-extra.com/html/icom/ic-7400/ic-7400_service-manual_612265087.webp)
12 - 4
5V
2SC4081
Q810
RTKI
0.0047
C788
4.7k
R814
4.7k
R811
MA2S111
D810
15k
R813
33k
R812
0.0047
C810
C1620 100p
C1621 100p
C1622 100p
C1623 100p
C1624 100p
R1620 47k
R1621 47k
R1622 47k
R1623 47k
[ACC (1)]
[ACC (2)]
[ALC]
[SEND]
unit J13
to CTRL
[EXT SP]
PAFE
SSP
PAFE
SSP
_SSTB
_SBSY
SPCH
GND
SPCE
5VL
MCK_UT
SBSY
SSTB
MDAT_UT
[REMOTE]
J1
to CHASSIS
GND
GND
EGND
E14V
EST
EKY
[DATA]
CP9011
CP9009
CP9002
CRSY
CTXD
CRXD
_H5VL
_NSQL
TFRA
RXF2
RXF1
RXF0
TXF3
TXF2
TXF1
TXF0
RXSO
TXSO
DLTX
_DRES
100k
R1912
100k
R1913
W304
5VL
CP1000
MAIN UNIT (2)
(1)
UNIT
MAIN
_H5VL
5VL
5V
14V
8V
W1940
FZMD
_H5VL
FZVP
FZRS
FZTX
FZRX
CP1624
CP1623
CP1622
CP1621
CP1620
CP1626
_H5VL
5VL
100k
R2040
0.1
C2040
FZMD
0.01
C1580
0.1
C1504
CP1581
CP1583
CP1582
22k
R1910
22k
R1900
_ASO2
ACCMOD
AAFO
EALC
SQL
14V
BAND
10k
R786
0.0047
C784
680
R791
680
R785
2SD1619
Q785
0.0047
C796
10k
R797
680
R793
680
R792
DTC114EU
Q787
2SD1619
Q786
0.0047
C795
680
R795
680
R794
10k
R796
DTC114EU
Q788
P2MS
DTA114EE
Q783
5V
8V
14V
TRAS
D782 MA2S111
R787 2.2k
D783 MA2S111
R788 2.2k
0.0047
C785
0.0047
C792
0.0047
C786
10k
R789
0.0047
C787
0.0047
C791
0.0047
C790
0.0047
C789
L786 100
µ
L787 100
µ
100
µ
L788
HF50ACC322513-B
L789
HF50ACC322513-B
L785
100
µ
L784
100
µ
L781
100
µ
L783
HF50ACC322513-B
L790
HF50ACC322513-B
L782
HF50ACC322513-B
L780
L793
RXS
144M SEND
HF & 50M SEND
5V
CP790
CP791
CP792
CP793
CP794
CP795
CP796
CP782
CP783
CP784
CP785
CP789
CP787
CP797
CP786
8
6
1
4
2
5
3
7
6
1
4
2
5
3
7
DTC114EU
Q784
0.0056
C794
DAN222
D784
10
R790
0.0047
C793
OMR-109F
RL781
J782
CP788
CP781
CP780
J781
J780
0.0047
C760
0.0047
C761
0.0047
C762
CIVE
CIV
START
14V
KEY
L763 HF70ACC635050-T
L762 HF70ACC635050-T
L761 220
µ
L760 220
µ
W760
100p
C763
CP760
CP761
CP762
CP763
CP764
CP765
J760
J761
0.0047
C702
0.0047
C703
0.0047
C704
0.0047
C705
0.0047
C706
DPTL
10
µ
L2060
0.0047
C701
R702 4.7k
MA2S111
D700
0.0047
C700
2SC4081
Q700
15k
R700
4.7k
R703
33k
R701
AAFO
DATA
DOUT
SQL
L700 100
µ
L701 100
µ
L702 100
µ
EXCCL3225U
L703
L704 100
µ
CP704
CP702
CP700
CP703
CP705
CP701
J700
5
3
1
2
4
6
W740
SPS
14V
14V
PAFO
DTC114EU
Q740
0.0047
C741
DAN222
D740
10
R740
0.0047
C740
AHY103
RL740
PAFE
CP740
L741
HF50ACC322513-B
HF50ACC322513-B
HF50ACC322513-B
L792
HF50ACC322513-B
L794
HF50ACC322513-B
L791
HF50ACC322513-B
HF50ACC322513-B
HF50ACC322513-B
L742
L740
L795
HF50ACC322513-B
L796
CP742
CP743
CP741
J740
J741
CP1921
CP1923
CP1920
CP1924
R1923 1k
R1921 1k
R1922 1k
MDAT
47k
R1920
0.0047
C1920
R1924 1k
MCK
0.01
C1921
CP1926
RV-150
R1925
SPCH
CP1925
CP1922
J1920
_TRAS
_SENI
_OVDK
_ISTA
_9K6S
_AFMS
_SQLS
_SQSS
_NBS
_UNSB
47k
R1562
FZVP
FZRS
MR
_MSL2
_MSL1
_2F15
_2F3K
_P2MS
_P50S
_PHFS
LTXD
LRXD
_AMS
_ASL
0.01
C1510
0.1
C1509
10
C1507
0.01
C1505
FZMD
FZMD
_H5VL
12p
C1506
12p
C1508
CR-520
X1500
SSTB
SBSY
0.1
C1512
0.1
C1511
0.01
C1561
FZRS
5VL
5VL
5VL
DRES
47k
R1561
0.0047
C1560
47k
R1560
HV
5
4
3
2
1
S-80942ANMP-DD6
IC1560
NC
CD
VSS
VDD
OUT
FZTX
FZRX
_NSQL
_DRQW
_DWBY
_DCK
_DDTW
MCK
MDAT
100k
R1941
100k
R1940
0.01
C1940
MA2S111
D1940
33k
R1945
6.8k
R1943
2SC4081
Q1941
2SA1576
Q1940
47k
R1942
8
7
6
5
4
3
2
1
TC7W04F
IC1940
15k
R1944
W1941
CIV
CIVE
_DRQR
_DDTR
_DRBY
_DSTR
_DCBY
_CTFL
_TOFF
_RTDT
_VSQL
_DSST
_DSKY
DRBY
DCBY
DWBY
DSTR
DRQR
DRQW
DDTR
DDTW
DCK
R1964 1k
R1965 1k
R1966 1k
R1967 1k
R1968 1k
R1969 1k
R1970 1k
R1971 1k
R1972 1k
47k
R1963
47k
R1962
47k
R1961
47k
R1960
_DCK
_DDTW
_DDTR
_DRQW
_DRQR
_DSTR
_DWBY
_DCBY
_DRBY
R1985 1k
R1986 1k
R1987 1k
R1988 1k
R1989 1k
R1990 1k
R1991 1k
NSQL
VSQL
TOFF
RTDT
CTFL
DSST
DSKY
0.0047
C1986
0.0047
C1985
0.0047
C1984
0.0047
C1983
0.0047
C1982
0.0047
C1981
0.0047
C1980
47k
R1984
47k
R1983
47k
R1981
_DSKY
_DSST
_CTFL
_RTDT
_TOFF
_VSQL
47k
R1982
47k
R1980
_NSQL
_PWRK _ANTS
_IKEY
_RTKI
W1610
W1609
W1608
W1607
W1606
W1605
W1604
W1603
W1602
W1601
W1600
R1512 220
CON2
R1511 220
PDAT
R1510 220
PCK
R1509 220
PST5
R1508 220
PST3
PST2
R1507 220
R1506 220
PST1
_UNLC
R1505 220
_UNLC
47k
R2000
0.0047
C2000
D2000 1SS385
UNLC
DRES
1k
R2042
0.0047
C2041
100k
R2041
1
2
3
5
4
TC7S04F
IC2040
_PWRS
R1504 220
FSTB
R1503 220
R1502 220
0.1
C1503
0.1
C1502
0.1
C1501
0.1
C1500
_SKYS
R1501 220
BSTB
R1500 220
ASTB
10k
R1581
22k
R1580
8
7
6
5
4
3
2
1
A0
A1
A2
VSS
VCC
WP
SCL
SDA
HN58X24128FPI
IC1580
_TXS
_RXS
_DTCS
ESTA
TCON
EKEY
_MODS
0.047
C1907
1M
R1901
R1909 1k
_BEEP
BEEP
_BEEP
_AVXL
_VOXL
_FMTL
_ASO2
_ASO1
_ASO0
_AVXL
_VOXL
_FMTL
0.0047
C1902
0.0047
C1901
0.0047
C1900
22k
R1911
22k
R1908
R1904 1k
R1903 1k
R1902 1k
AVXL
VOXL
FMTL
RB706F-40
D1901
RB706F-40
D1900
_ASL
FORL
THML
_ASO0
_ASO1
0.0047
C1904
R1905 1k
R1906 1k
0.1
C1908
R1907 1k
0.0047
C1906
ALCL
DPTL
REFL
BU4O503BCFV
IC1900
C
B
A
X0
X1
X
Y
VDD
VSS
VEE
INH
Z0
Z
Z1
Y0
Y1
16
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
ESTA
EKEY
TCON
_SQSS
_AFMS
_SQLS
_TXS
_RXS
_TRAS
_SENI
_RTKI
_SKYS
_OVDK
_MSL2
5VL
5VL
5VL
5VL
5VL
5VL
_MSL1
_2F15
_2F3K
_P2MS
_P50S
_PHFS
_AMS
MR
_DTCS
_MODS
_9K6S
_NBS
_UNSB
_ANTS
_PWRS
LTXD
LRXD
_PWRK
_IKEY
_H5VL
5VL
_ISTA
5V
_H5VL
_H5VL
1M
R1882
47k
R1883
R1881 1k
R1880 1k
DA221
D1881
DA221
D1880
DTC114EU
Q1880
0.0047
C1880
0.0047
C1881
L1881 10
µ
L1880 10
µ
KEY
START
47k
R1863
47k
R1864
0.0047
C1862
0.0047
C1861
0.0047
C1860
DTC114EU
Q1860
SQL
R1862 1k
AFMS
R1861 1k
R1860 1k
SQLS
47k
R1853
22k
R1852
47k
R1851
47k
R1850
0.0047
C1846
0.0047
C1845
0.0047
C1844
0.0047
C1842
0.0047
C1841
0.0047
C1840
DA221
D1841
DA221
D1840
47k
R1840
R1847 1k
D500 1SS133
W500
TXS
SEND
R1846 1k
RXS
R1845 1k
TRAS
SENI
R1844 1k
R1843 1k
RTKI
SKYS
R1842 10k
R1841 10k
OVDK
MA2S111
D1826
MA2S111
D1825
MA2S111
D1824
MA2S111
D1823
MA2S111
except [USA]
D1822
47k
R1828
0.0047
C1827
0.0047
C1826
0.0047
C1825
0.0047
C1824
0.0047
C1823
0.0047
C1822
0.0047
C1821
0.0047
C1820
R1827 1k
MSL2
R1826 1k
MSL1
R1825 1k
2F15
R1824 1k
2F3K
R1823 100
P2MS
R1822 1k
P50S
R1821 1k
PHFS
AMS
R1820 1k
0.0047
C1803
0.0047
C1802
0.0047
C1801
0.0047
C1800
0.0047
C1804
R1804 1k
MODS
R1803 1k
9K6S
R1802 1k
NBS
R1801 1k
UNSB
R1800 1k
0.0047
C1760
0.0047
C1780
ANTS
R1780 1k
PWRS
R1760 1k
47k
R1743
47k
R1742
LMFD
R1741 1k
LFMD
R1740 1k
5V
8V
14V
_H5VL
10
C2020
0.1
C2021
0.1
C2022
L2061 1
µ
L2020 1
µ
R1721 47k
0.0047
C1720
R1720 1k
PWRK
R1703 47k
47k
R1702
0.0047
C1701
0.0047
C1700
R1701 1k
IKEY
R1700 1k
ISTA
PG2/CS2
PG1/CS3
PG0/CAS
MD2
MD0
MD1
P10/PO8/TIOCA0
P11/PO9/TIOCB0
P12/PO10/TIOCC0
P13/PO11/TIOCD0
P14/PO12/TIOCA1
P15/PO13/TIOCB1
P16/PO14/TIOCA2
P17/PO15/TIOCB2
VSS
AVSS
P47/AN7/DA1
P46/AN6/DA0
P45/AN5
P44/AN4
P43/AN3
P42/AN2
VREF
AVCC
P41/AN1
P40/AN0
PF0/BREQ
WDTOVF(FWE)
P53/ADTRG
P52/SCK2
VSS
P51/RXD2
VSS
PF1/BACK
P50/TXD2
PF2/LCAS/WAIT
PF3/LWR
PF4/HWR
PF5/RD
PF6/AS
VCC
PF7/FAI
VSS
EXTAL
XTAL
VCC
STBY
RES
NMI
P20/PO0/TIOCA3
P21/PO1/TIOCB3
P22/PO2/TIOCC3
P23/PO3/TIOCD3
P25/PO5/TIOCB4
P24/PO4/TIOCA4
P26/PO6/TIOCA5
P27/PO7/TIOCB5
P63/TEND1
P62/DREQ1
P61/TEND0/CS5
VSS
VSS
VSS
P60/DREQ0/CS4
P35/SCK1
P34/SCK0
P33/RXD1
P31/TXD1
P32/RXD0
P30/TXD0
VCC
PD7/D15
PD6/D14
PD5/D13
PD4/D12
VSS
PD3/D11
PD2/D10
PD1/D9
PD0/D8
PE7/D7
PE6/D6
PE5/D5
PE4/D4
VSS
PE3/D3
PE2/D2
PE1/D1
VCC
PE0/D0
P64/IRQ0
P65/IRQ1
VSS
PC66/CS6/IRQ2
PC67/CS7/IRQ2
PA7/A23/IRQ7
PA6/A22/IRQ6
PA5/A21/IRQ5
VSS
PG4/CS0
PG3/CS1
NC
VCC
PC0/A0
PC1/A1
VSS
PC3/A3
PC2/A2
PC4/A4
PC6/A6
PC5/A5
PC7/A7
PB0/A8
PB1/A9
PB2/A10
PB3/A11
VSS
VSS
PB4/A12
PB5/A13
PB6/A14
PA0/A16
PA1/A17
VSS
PA3/A19
PA2/A18
PA4/A20/IRQ4
PB7/A15
128
127
126
125
124
123
122
121
120
119
118
117
116
115
114
113
112
111
110
109
108
107
106
105
104
103
102
101
100
99
98
97
96
95
94
93
92
91
90
89
88
87
86
85
84
83
82
81
80
79
78
77
76
75
74
_NSQL
73
72
71
70
69
68
67
66
65
64
63
62
61
60
59
58
57
56
55
54
53
52
51
50
49
48
47
46
45
44
43
42
41
40
39
38
37
36
35
34
33
32
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
HD6432357A26F
IC1500
BUS LINE2
BUS LINE1
5V
14V
8V
H5V
CP1625
EP761
EP760
EP781
EP780
EP783
EP782
EP784
EP790
EP786
EP788
MAIN UNIT (2)
2.5V
0.05
µ
sec
3.9V
0.05
µ
sec
4.9V
4.9V
0V
0V
4.7V
2.4mV
30.6mV
Is there a plug in phone of front?
yes: 13.64V
no: 0.065V
144M
TX: 7.56V
RX: 7mV
HF+50M
TX: 4.7V
RX: 0V
HF+50M
TX: 7mV
RX: 7.56V
HF+50M
TX: 0.748V
RX: 0V
144M
TX: 0.768V
RX: 0V
13.63V
TX: 0.75V
RX: 3mV
SQL ON: 7.85V
OFF: 0V
Range
Digital tester
Voltage at RX(No designation)
MEASUREMENT CONDITIONS
frequency: 14.1MHz USB
RX (no input)
200mV
2V
20V
Input resister
100M
Ω
11M
Ω
10M
Ω
Oscilloscope(20MHz,1M
Ω)
12-4 MAIN UNIT (2)
Summary of Contents for IC-7400
Page 1: ...HF VHF TRANSCEIVER i7400 SERVICE MANUAL ...
Page 63: ...to S LOGIC board J303 DS1002 9 2 DISPLAY BOARD TOP VIEW 9 3 for free by RadioAmateur eu ...
Page 72: ...9 12 1 9 18 10 BOTTOM VIEW RF UNIT for free by RadioAmateur eu ...
Page 74: ... BOTTOM VIEW CTRL UNIT 9 14 for free by RadioAmateur eu ...
Page 76: ... BOTTOM VIEW TUNER UNIT 9 16 for free by RadioAmateur eu ...
Page 78: ...9 18 BOTTOM VIEW PA UNIT for free by RadioAmateur eu ...
Page 92: ...1 1 32 Kamiminami Hirano ku Osaka 547 0003 Japan S 13811HZ C2 2002 Icom Inc ...