Icom IC-M304 Service Manual - page 27
11 - 2
C112
R:3.48V
R:0.42V
R:3.93V
R:0.23V
R:2.37V
R:7.55V
R:2.14V
R:3.62V
R:4.26V
4.29V
3.84V
R:2.04V
T:4.78V
Hi :2.87V
Low:1.43V
R:2.78V
4.73V
R:7.72V
R:1.91V
470P
C236
100P
C67
0.001
C6
R148
1.8K
8.2K
R95
470
R201
22P
C138
R35
100K
10
C276
47
R188
6.8K
R32
2SC4226
Q13
R139
2.2K
R140
10K
CR-804A
X2
0.0068
C86
C60
0.01
0.
1
C28
56P
C115
DSA3A1
D25
3.9K
R225
0.1
C82
10
R110
0.001
C242
12K
R190
HVC350B
D13
5P
C16
6P
C135
0.01
C215
270
R128
47P
C295
47K
R26
22
C161
Q2
3SK13 1
0.01
C71
LW-25
L32
0.
1
C223
470
C211
220K
R65
0.001
C232
0.01
C102
C145
0.001
15K
R62
100P
C198
R9
100K
68K
R97
KDV214E
D7
33K
R68
27K
R103
R8
1
10
C118
TC7W66FU
IC7
1
2
3
4
5
6
7
8
1.5K
R51
0.
1
C72
0.
1
C228
22K
R61
0.
1
C226
0.001
C57
2.7K
R165
R6
47K
0.001
C278
390
R92
0.047
C61
1
C216
0.5P
C29
Q33
KTA2015
7P
C31
R146
1.8K
R7
560
33K
R69
1.5M
R25
KTC4075
Q36
0.001
C46
47K
R48
4.7K
R226
0.
1
C76
C172
0.001
1.2K
R33
LA4425A
IC6
1
2
3
4
5
1.8K
R147
2.2K
R38
470
R3
9
0.
1
C89
0.
1
C274
FMW1
Q21
1
2
3
4
5
68K
R41
10
R212
47
R206
CP2
CP06VR
100K
R16
1P
C14
UPD3140GS
IC8
1
VCC1
2
IN1
3
ENB
4
CLK
5
DATA
6
T1
7
LOK
8
CP1
9
FI1
10
FO1
11
FO2
12
FI2
13
CP2
14
GND2
15
XO
16
XI
17
XB
18
VCC2
19
IN2
20
GND1
2685
MP 3
1
470P
C302
68K
R202
KTA1664
Q35
100K
R12
LS-440
L6
22P
C245
2.2 MSVA
C254
120P
C225
390
R44
0
R77
0.001
C114
470P
C182
1M
R161
L1
LA-243
N
TCG16
R47
OPC-1264
To VR and SQL UNITs
To HM-164
A
W1
1
2
3
4
5
6
7
8
10K
R111
0.001
C146
82K
R179
47P
C116
7P
C23
2P
C30
0.0022
C85
0.001
C251
22K
R27
33K
R87
NJM4558M
IC10
6
5
7
0.001
C176
0.0068
C83
CP1
CP06VR
KTA2015
Q23
1.5K
R43
KTC4075
Q11
R37
470
R1
0
33
4P
C34
KDV214E
D6
270
R113
0.75P
C128
0.001
C186
0.
1
C63
0.001
C178
100P
C202
0.1U
L23
470P
C277
100K
R126
3.5P
C22
470P
C35
1.5P
C125
R137
82
D26
K
DS12 2
470P
C164
Q1
3SK131
LS-440
L8
1.2K
R46
0.
1
C52
C185
470P
47P
C147
R21
100
47N
L29
R5
39K
0.01
C184
0
R17
0.022
C84
10P
C151
33K
R53
0.001
C64
82K
R191
47P
C300
5P
C153
1922
MP 1
1
2
3
1K
R85
3P
C24
C181
0.001
10K
R45
D8
MA742
L2
LA-243
0.1U
L35
R134
100K
FI 1
FL-368
10
C230
470P
C206
270
R205
39K
R75
10K
R54
0.001
C126
0.001
C139
15K
R183
2.2K
R213
2.2K
R222
0.01
C250
0.001
C5
9
27P
C7
L308CCB
D1
150P
C140
1
R158
220
R129
1K
R82
KTC4075
Q5
22P
C171
C180
0.001
R4
100K
0.1U
L28
47k
R184
CP10S
CP7
4.
7
R152
220P
C74
D21
HSM88ASR
2.7K
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LS-440
L9
7P
C26
15K
R153
470
R6
3
0.001
C136
0.
1
C222
10K
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1K
R57
470P
C203
1
C122
10
C104
0.
1
C75
2.2K
R211
NJM4558M
IC10
V+
8
GND
4
1.5P
C127
MA2S077
D12
10K
R55
C55
5P
560P
C94
100
R102
8.2K
R93
0.
1
C212
NJM4558M
IC10
2
3
1
3.3K
R216
100
R86
0.001
C148
22K
R174
0.01
C130
10
C22
7
0.01
C18
0.033
C99
0.01
C110
18P
C5
470
R42
470P
C162
0.1 SVA
C113
2.2K
R127
Q19
KRC404
0.0022
C93
10P
C149
47K
R170
2SC4226
Q14
FI 2
FL-399A
KDV214E
D5
0.68 MSVA
C252
15K
R76
470P
C117
18P
C259
KIA7805API
IC9
I
O
COM
470
C213
470P
C199
Q20
KRC404
220P
C73
2.2K
R108
0.
1
C249
220
R135
47
R71
0.022
C91
72.0N
L22
KRC404
Q12
0.001
C217
470K
R64
LA-253
L31
470P
C297
0.001
47K
R84
1M
R155
0.022
C90
KTC4075
Q7
0.22
C103
Q22
KRC402
390
R67
330
R215
LT450EW
FI3
I
O
12P
C258
1.8K
R149
0.
1
C17
TA31136FNG
IC1
1
OSCI
N
2
OSCOUT
3
MIXOUT
4
VCC
5
IFIN
6
DEC
7
FILOUT
8
FILI
N
9
AFOUT
10
QUAD
11
I
FOUT
12
RSSI
13
N-DET
14
N-REC
15
GND
16
MIXI
N
1K
R106
0.001
C49
22P
C8
10
C279
10K
R56
Q34
KRC404
2.7U
L21
470K
R72
4.
7
C248
R181
NTCG16
1.5K
R36
0.01
C97
68
R130
Q31
KTA2015
100P
C234
L308CCB
D2
0.
1
C214
1M
R162
1M
R164
27K
R176
100
R91
0.
1
C270
470P
C292
18
R204
CP3
CP10S
0.001
C304
470P
C296
5P
C241
10K
R157
L3
LA-243
680
R96
0.001
C207
0.001
C77
10K
R141
KTC4075
Q6
2.2K
R70
15K
R112
470P
C280
4P
C4
22
C167
0.
1
C5
0
390
R109
0.1
C100
150
R171
0.001
C221
0.01
C307
0.001
C44
18K
R52
10
C68
R144
3.3K
10P
C48
68K
R177
10K
R223
D22
HSM88ASR
0.0022
C101
1K
R81
S5B-PH-K- S
J2
1
1
2
2
3
3
4
4
5
5
X1
JTB450C24
1
R159
330
R214
0.001
C124
CP5
CP10S
0.001
C303
0.
1
C88
100K
R74
270
R203
0.001
C27
0.001
C275
100K
R89
100K
R172
0.22
C220
22P
C201
68N
L36
47
R210
100P
C165
0.1U
L12
180
R94
0.1U
L13
CP4
CP10S
0.001
C208
0.001
C36
10
C92
0.001
C166
10K
R221
100P
C159
10
C111
0.001
C70
0.01
C177
10P
C257
270K
R50
470P
C301
Q25
KRC404
0.001
C246
2SC4226
Q17
47P
C299
1K
R224
R34
1.2K
MA2S077
D1 1
0.
1
C21
KDV214E
D4
47P
C306
2SC4215
Q15
22P
C244
10K
R138
0.001
C298
470P
C179
0.001
C247
HVC350B
D14
18P
C243
LS-440
L7
0.001
C20
MA2S077
D17
1
C95
0.1U
L26
30FLT-SM2-TB
J1
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
10K
R173
47K
R73
10
C273
0.001
C175
0.01
C62
7P
C15
0.001
C121
R78
2.2K
0
.01
C53
Q26
KTC4080
0.001
C305
2SC4215
Q16
10
R31
0.
1
C105
Q4
KTC4080
0.001
C80
C173
0.001
22K
R156
22K
R88
100
R151
0.001
C19
8.2K
R90
82K
R178
CP10S
CP6
8P
C12
NJM2211M
IC3
1
V+
2
IN
3
LOCK
4
GND
5
Q
6
Q
7
DATA
8
FSK
9
NC
10
REF
11
LOOP
12
R
13
CAP
14
CAP
Q32
KRC404
5P
C174
0.0039
C233
D9
1SS32
1
0.001
C205
0.001
C65
56P
C47
3.5P
C32
0.001
C294
3.5P
C42
470P
C291
10P
C1 3
0.001
C119
1.2K
R154
0.001
C129
4.7K
R136
27P
C3
560
R83
3.5P
C25
8.2K
R189
10
C269
0.82U
L10
22
R145
100K
R14
10K
R58
100P
C194
1K
R49
MA2S077
D16
27K
R180
RCV
SEND
PTT
H/
L
BEEP
SQLV
WXDE C
DSCDEC
RCV
TMUTE
TXDET
H/ L
PSTB
PDATA
SP+
SQ
L
SQL
V
SQLI
WXDEC
PSTB
PCK
PDAT
A
PCK
SEND
BPF
SQLC
SQ L
KEYM
PTT
PTTC
RMUTE
DSCENC
BPLVL
SQLC
SQLI
SQL V
KEYM
TM
U
T
E
UNLK
UNLK
DETO
BPLVL
BEEP
TXDET
DSCENC
RMUTE
PTTC
HVS
HVS
R8
R8
R8
BPF
R5
R5
DSCDEC
5V
5V
T5
SP+
DETO
VCC1
VCC2
OUT
IN
HVS
VOL1
VOL2
GND
HV
SQLI
SQLV
GND
SP-
PTT
GND
MIC
M ICG
KEYM
IC4
HV
GND
ANT
SP+
SP-
LV
RSSI
RX LINE
TX LINE
COMMON LINE
DATA BUS
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