Icom IC-7400 Service Manual page 71

SECTION 12 VOLTAGE DIAGRAM
• FRONT UNIT (1/2)
RUP J502 RUP
5VL
5VL
RDN RDN
GND GND
GND GND
GND GND CP523 CP521
GND GND CP522
GND GND
GND GND CP504 CP502
GND GND CP505 CP503 CP501
5VL J501 5VL
PB1A PB1A
PB1B PB1B
MCHA MCHA
MCHB MCHB
PB2A PB2A
PB2B PB2B
GND GND
GND GND
GND GND
CP572 CP574
CP571 CP573 CP576
PAFE J507 PAFE
PAFO PAFO
PAFE PAFE
R571
GND GND
22k
PHNL PHNL
DASH DASH
DOT DOT
GND GND
GND GND
GND GND
J508
EP701
MIC MIC
CP701
M8V M8V
CP702
MUD MUD
SQLS SQLS
CP704
MSEND MSEND
CP706
GND GND
CP705
MMICE MMICE EP703
CP707
PAFO PAFO
CP708
J601 SPS
CP710
PAFO
CP711
PAFE
CP712
LFMD
LMFD
GND
SRES
PWRK
CP716
SQL
CP717
SEND
CP718
to
MICE
MAIN CP719
MIC
unit CP720
GND
J1334
CP721
-8V_
GND
L601
GND
SLF7032T-101MR45-2
5VL
5VL
GND
8V
GND
14V
S601 SKQDPA
[POWER]
CP722 CP723 CP724
PB2A
CP5 CP4 CP3 CP2 CP1
J1
PB2B
5VL 5VL GND
PB1A PB1A PB1A
PB1B PB1B
PB1B
MCHA MCHA GND
MCHB MCHB
PB2A PB2A
PB2B PB2B
GND GND
GND GND
GND GND
MCHA
MCHB
GND
PBT BOARD
CP3 CP2 CP1
J1
RUP RUP
5VL 5VL
RDN RDN
GND GND
GND GND
GND GND
GND GND
GND GND
GND GND
GND GND
RUP
RDN
NR/NOTCH
R2
1k
PB3
[NOTCH]
PB2
[NR]
P14
R3
1k R306
4.7k
[AF/RF]
R5
1k
PB1
IC571 [RF ]
TC4S71F
5
D573
1
4 PB0
DA221
2 [AF]
R6
3
1k
DASH
DOT
-8V
8V
5V
CP703 S-LOGIC UNIT
C401
L401
(page 28)
0.1
D10F-A814AY-681K [MIC
GAIN]
C402
470
R403
8.2k
[RF
CP714
PWR]
CP713 CP715
C403
0.1
C404
220
[CW
IC401
C405
NJM2360AM PITCH]
270p
L402
D10F-A814AY-221K
D402
SB10-05PCP
C407
[KEY
0.1
SPEED]
L403
D10F-A814AY-681K
R16
S8
R15
SKQDPA
6.8k
C9
0.1
[P.AMP/
ATT]
CP8 CP7 CP6 CP5
J2
MIC MIC L1 100µ
[PBT] M8V M8V
MUD MUD L3 100µ
S2
TP90D96E20-30F-2178-1 SQLS SQLS L4 100µ
MSEND MSEND
2
A
3 GND GND
B PBT2
1 MMICE MMICE L6 100µ
COM
5 PAFO PAFO
A
6 NC
B PBT1
4 NC
CP1 CP2 CP3 CP4
COM
[M-CH]
S1
TP90N00E20-22.5-2494
MIC BOARD
2
A
3
B
1
COM
CP5 CP4 CP3 CP2 CP1
L1
J3
HF50ACC322513-B
PAFE PAFE
PAFO PAFO
R1 180
PAFE PAFE
S1
EVQ-VCJF0324B GND GND
R2 180
4 PHNL PHNL
COM
3 DASH DASH
NC L2
2 DOT DOT
HF50ACC322513-B
B
1 GND GND
A
GND GND
GND GND
[RIT/ TX]
RIT BOARD PHONE BOARD
12 - 1
P41
P42
CP306
CP307
CP308
CP309
Q302
2SB1201
CP310
L302 L303
100µ D818HN-1107
R301 CFL+
Q301 CP311
6.8k 2SC4081
CFL- CP312
D301 CP313
C305
RD3.0M
CP314
12p
CP315
CP317
CP318
CP316
Q303 Q304 CP325
2SC3647 2SC3647
R104 1M CP329
R102 R103
220k 100k CP330
R8
8
1k 10 P15 CP331
PB4 9
CP332
IC101c CP333
CP334
R108 1M CP335
R106 R107
220k 100k CP336
12
11 P17
R10
13
1k CP338
PB5
IC101d CP339
CP340
8
10 CP341
9
CP342
IC102c 14
R111 CP343
1
15k BU4030BF
3 P16 CP344
R12
2
IC102b
1k CP345
R112
PB6 14
BU4030BF
1 47k 7 CP337
3 5
2 4 P21 CP346
6
CP347
7 IC101a
IC102a MC14071BFEL
IC102d
BU4030BF
BU4030BF
5 S6 S7
R14
4 12
SKQDPA SKQDPA
1k 6 11
PB7 13
IC101b R113
15k
[CALL] [LOCK/SPCH]
2.2k R17 4.7k R18 15k
S9 S10 S11 S1 S2 S3 S4 S5
SKQDPA SKQDPA SKQDPA SKQDPA SKQDPA SKQDPA SKQDPA SKQDPA
[NB] [VOX/ [TRANSMIT] [TUNER] [ANT] [NR] [A/NOTCH]
BK-IN]
[MONITOR]
C1
0.0047
J1
FM214-BSS(P)
F2 F1
1 7
2 8 6
3 5
4
F3 F4
F5 MENU
J1
HLJ5305-01-4090
CW/
SSB
RTTY
[PHONES]
J2
HLJ7000-01-3010
AM/
FILTER
FM
MODE BOARD
[ELEC-KEY]
CP304 DISPLAY BOARD
CP303 CP305
J301
J1001
5VL 5VL
5VL 5VL
GND GND
P14 P14 BKL BKL
P15 P15 RSA RSA
P16 P16 MSA MSA
P17 P17 RSB RSB
P41 LMFD LMFD
P42 LFMD LFMD
P21 P21 MSB MSB
GND GND
CP1022 CP1021 CP1020
PB1A PB1A PB1A
PB1B PB1B PB1B
MDNK MDNK MDNK
MUPK MUPK MUPK
SRES SRES SRES
-8V -8V
P67 P67 LOCK LOCK
P66 P66 SPEK SPEK
-8V -8V -8V
8V 8V
GND GND
CP328
W19
CP1026 CP1031 CP1032 CP1025
J302 J1002
W20
PB0 AFL AFL PB0
PB1 RFL RFL PB1
PB0 PB2 NRL NRL PB2
PB1 PB3 APFL APFL PB3
PB2 PB4 MIGL MIGL PB4
PB3 PB5 PWRL PWRL PB5
PB4 PB6 RITL RITL PB6
PB5 PB7 KYSL KYSL PB7
PB6 PC2 MUD MUD
PB7 DASH DSHK DSHK
DOT DOTK DOTK
DASH P54 APFK APFK
DOT P53 NRK NRK
P54 P52 ANTK ANTK
P53 P51 TUNK TUNK
P52 P50 TRAK TRAK
P51 KIO KIOI KIOI
P50 PB2A PB2A
KIO PB2B PB2B
PC2 GND GND
CP348
PB2A GND GND CP1042
PB2B GND GND CP1043
CP302 CP1044
CP301
CP1045
J303 CP1046
CFL+ CP2001
CFL
CFL-
CP603
CP604 DS1002
MBS 3 UA1W 70N ASSY
J604
5VL
MUP
to
C1205 0.0047
MDN MAIN
DIAL
CP605
R15 R3 R2 R1
6.8k 6.8k 6.8k 6.8k
C4 C3 C2 C1
J1
0.1 0.1 0.1 0.1
MNUK MNUK
F1K F1K
F2K F2K
F3K F3K
F4K F4K
F-INP 7 3.5 1.8
F5K F5K
SSBK SSBK
CWRK CWRK
AFMK AFMK
18
SPLIT 14 10
FILK FILK
GND GND
GND GND
GND GND
A/B 28 21
24
GND GND
GND GND
GND GND
GND GND
TS 144 GENE
50
GND GND
GND GND
GND GND
DS4
GND GND
CL-220YG
GND GND FIND
DS5
CL-220YG
R23 R24
SPLD MPRK
MP-R
6.8k 2.2k
DS3
CL-220HR
LOCD
MPWK
DS2 MP-W
CL-220YG
RIT TX
RXD
DS1
XFCK
CL-220HR
XFC
TXD
W22
NOTICE: Refer to the PARTS LIST for the value and name of each component.
A
B
C
D
CP1050 CP1051
E
F
G
H
I
J
K
L
M
CP1027
N
O
P
D1002
CP1017 MA2S111
CP1018
Q
IC1002
BU4051BCF
16
KI0 13 3
X0 X R
KI1 14
X1
KI2 15
X2
KI3 12
X3
KI4 1
X4
KI5 5
X5
KI6 2
X6
KI7 4
X7
S
6
INH
11
A
10
B
9
C
7 8
R1131
1k
SRES
T
U
V
CP1024 CP1023
R1133
1k
MDNK
W
R1134
1k
MUPK
X
Y
Z
a
b
c
d
KI0
e
f
J1
LDV
5VL
KI2
KI3
KI4
KI5
KI6
KI7
XFCK
MPWK
MPRK
W21
TXD
g
RXD
LOCD
SPLD
FIND
GND
GND
GND
GND
GND
GND
R19
6.8k
KI6
C5
0.1
V/M CALL
R25
4.7k
R20
2.2k
CLEAR MW M-CL
2.2k
R20
TEN-KEY BOARD
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