Section 8 Voltage Diagram - Icom IC-7851 Servise Manual

SECTION 9. VOLTAGE DIAGRAM
LDPS
1
H3R3V
SBPS
2
BRIV
BRIGHT 3
CNTV
4
5
6
7
8
MOND
9
CONTRAST
MNRD2
10
SNRD2
J1 11
STBD
H3R3V 12
1
PWRD
BRIL R11 4.7K
13
2
CNTL R12 4.7K ANTI VOX VOXD
3 14
AVXL R13 4.7K
TN1D
4
15
VOXL R14 4.7K
TN2D
5
16
DRVL R15 4.7K
6 TMD
17
CMPL R16 4.7K
7
MAGD
MONL R17 4.7K 18
8
MNRD1
GND
19
9
MNBD
GND
20
10 VOX GAIN
SAGD
21
SNRD1
22
SNBD
23
TRAK
24
PWRK
25
KI7
26
DRIVE
KI8
27
KI9
28
KI10
29
KI11
30
COMP MIGL
31
PWRL
32
MAGL
33
MSQL
34
KYSL
35
DELL
36
SAGL
37
MONI GAIN
SSQL
38
VR-E UNIT
39
H3R3V
40
J3
R1
RV-317
R3
4.7K
R4
MIC/PWR VR
4.7K
J1 J1
H3R3V H3R3V
1
R2 10
RV-317
R5 2
9
MIGL MIGL
8 3
PWRL PWRL
4
4.7K 7
MAGL MAGL
5
6
MSQL
MSQL
R6 6
5
MAIN AGC/SQL VR GND GND
4 7
GND GND
8
4.7K 3
GND GND
9
2
GND
GND
10
1
VR-A UNIT
R1
RV-317
R3
4.7K
R4
KEY/DELAY VR
J1
4.7K J2
H3R3V H3R3V
1
R2 10
RV-317
R5 9 2
KYSL KYSL
3
8
DELL DELL
4
4.7K 7
SAGL SAGL
5
6
SSQL SSQL
R6 5 6
SUB AGC/SQL VR GND GND
7
4
GND GND
8
4.7K 3
GND
GND
2 9
GND
GND
1 10
VR-B UNIT
J2 J1
9 R5 27 SDDAT2
DAT2 1
1 R6 27 SDDAT3
CD/DAT3 2
2
R7 27 SDCMD
CMD
3
3
GND
VSS1
4
4 EP4 MPZ1608S601A VDD(3R3V)
VDD 5
5 R8 27 SDCLK
CLK 6
6 GND
VSS2
7
7
R9 27 SDDAT0
DAT0
8
8
R10 27 SDDAT1
DAT1
9
SDCD
CD1 10
R1 220 SDWP
CD2 11
SDBD
WP1
12
R2 220 USBD
WP2
13
LDPS
14
DS24
SMLA13BC8T
DS23
SMLA13BC8T
USB ACCESS LED
SD UNIT
SD ACCESS LED
STBV
LDPS
BRIV
CNTV
R1
STBD DS5 STBY LED
SML-512DW
1k
SDBD
R2
USBD PWRD DS6 POWER ON LED
SMLE13BC8T
1k
S1
POWER SW
LS8J2M
VOXD DS12
B1931TX
R14
S11
4.7K
S2
TRANSMIT SW
LS8J2M
LS8J2M
MOND DS17
B1931TX
R3
DS15 TUNING LED S21
TN1D
SML-512UW
1.8k
R4
TN2D DS16 TUNER LED
B1931TX
820
KI11 LS8J2M
S3
TUNER SW
LS8J2M
TMD DS7 TIMER LED
B1931TX
R13
S4
2.2K
TIMER SW
LS8J2M
DS8 DS9
B1931TX B1931TX
DS18
SMLE13BC8T
S6 S5
LS8J2M LS8J2M
MAIN MAIN
AGCVR SW NR SW
R15 R16
2.2K 4.7K
TO SPEAKER TO MAIN J413
SPO
SPO 1 1
SPE
SPE 2 2
J106 J105
R201
100k
IC201
1 5
C201
2
3 4
0.01
SN74LVC1G04DCK
J104
LDPS
1
USBD
2
SDBD
3
SDWP
4
SDCD
5
SDDAT1
6
SDDAT0
7
GND
8
SDCLK
9
VDD
10
GND
11
SDCMD
12
SDDAT3
13
SDDAT2
14
SW-A UNIT
J101
9-1
S14
A
LS8J2M
S15
J1
B
PHE L4 100U EP1
1
PHOM L5 100U EP2
2
PHE
3
LS8J2M PHOS L6 100U EP3
4
PHE
5
PHI
6
GND
S16
7
DASH
8
DOT
C 9
GND
10
VOX BK-IN SW
LS8J2M
S17
D
LS8J2M
MONI SW
S18
E
J2
100U
MICI L1
1
M8V
2
100U
LS8J2M MUDL L2
3
SQSS
L3
4
100U
MSND
5
S19
6
EP12
7
MMZ1608D301B
MICE MPZ1608S221A
F
8
9
AFO
10
LS8J2M
100U L4
S20
G
LS8J2M
DS10 DS11 DS13 DS14
B1931TX B1931TX B1931TX
B1931TX
DS19
SMLE13BC8T
S7 S8 S12 S13
LS8J2M LS8J2M LS8J2M LS8J2M
MAIN SUB SUB SUB
NB SW AGCVR SW NR SW NB SW
R17 R18
4.7K
2.2K
TO LCD
J2
DS4
DS7
R4
MPZ1608S221A
R1 SMLA12WBC7W
MPZ1608S221A 0
SML-A12WT
10 PHONE-J
R2
MPZ1608S221A
DS3
DS6
10
SML-A12WT
L103 SML-A12WT
J103
DS2
100U DS5
SML-A12MT
EP102
MAIN RX
MMZ1608Y102BT
SML-A12UT
L102
MAIN LOCK
ELEC-KEY-J
EP101 L101 100U
SPLIT
100U
MMZ1608Y102BT
SUB TX
SUB RX
SUB LOCK
JACK UNIT LED UNIT
R1
C1 C8 R3
RV-325
0.01
4.7K
47P
MMZ1608Y102BT EP11 1
MMZ1608Y102BT EP4 7
7 1
MMZ1608Y102BT EP5 2 R4
SUB NR/NB VR
8
MPZ2012S601A EP7 4.7K
6
6 8 2
MMZ1608Y102BT EP2 3
R2 R5
MMZ1608Y102BT EP3 4
RV-325
5
R6 5 3 4.7K
0
4
EP9
EP8
J1
R6
MPZ2012S601A SUB AF/RF VR
4.7K
EP10
MMZ1608D301B MIC UNIT VR-D UNIT
VR-C UNIT
J2
1
2
PHOS
EP9
3
PHE EP6
4
PHOM EP7
5
EP8
6
7
R26
8
0
MPZ2012S601A
J3
PHE
10
PHOM
9
8
PHOS
7
6
PHNI EP5
5
EP4
4
DSHK EP3
3
DOTK EP2
2
EP22
1
MPZ2012S601A
J4
EP20
MICI
10
EP19
9
EP18
8
EP17
7
MSND EP16
6
MPZ2012S601A
5
EP14
R1 4
MICE EP13
RV-325
3
R3
EP12
2
AFO EP10
4.7K
1
MPZ2012S601A
R4
MAIN NR/NB VR
4.7K
J1
H3R3V
1
R2
RV-325
R5 2
MNRL
3
4.7K MNBL
4
MAFL
5
MRFL
6
R6
MAIN AF/RF VR
7
DOTK
4.7K
8
DSHK
9
PHNI
10
11
M8V
12
MUDL
13
SQSS
14
MSND
15
16
17
18
*: Refer to the PARTS LIST for the value and name of component.
TO DISPLAY J1
TO DISPLAY J11
TO DISPLAY J2
TO DISPLAY J3
DS1
SML-A12UT
J1
LDPS
1
MAIN TX MTXD
2
MRXD
3
MLCD
4
SPLD
5
STXD
6
SRXD
7
SLCD
8
9
10
J1
H3R3V
10
9
SNRL
8
SNBL
7
SAFL
6
SRFL
5
4
3
2
1
SW-B UNIT
J1
F1K
1
F2K
2
F3K
3
F4K
4
F5K
5
F6K SSBK F1K
6
F7K S8 S1
7
SSBK
8
CWK
9
RTYK
10
AMK
11
DATK LS8J2M LS8J2M
12
MSCK SSB
F-1
13
EXTK
14
RECK
CWK F2K
15
PLYK
S9 S2
16
MATK
17
GND
18
LS8J2M LS8J2M
CW
F-2
RTYK F3K
S10 S3
LS8J2M LS8J2M
RTTY/PSK
F-3
AMK F4K
S11 S4
RECK
S15
LS8J2M LS8J2M
AM/FM
F-4
DATK F5K
LS8J2M
S12 S5
REC
LS8J2M LS8J2M
PLYK
DATA
F-5
S16
MSCK F6K
S13 S6
LS8J2M
PLAY
LS8J2M LS8J2M
M.SCOPE
F-6
EXTK F7K
MATK
S14 S7
S17
LS8J2M LS8J2M
LS8J2M
EXIT/SET F-7
AUTO TUNE MAIN
TO DISPLAY J9
TO DISPLAY J8