![background image](http://html.mh-extra.com/html/icom/ic-m504/ic-m504_service-manual_612820032.webp)
VOLTAGE LINE
Explanatory notes
TX LINE
RX LINE
COMMON LINE
NJM4558M
IC7
1
2
3
4
5
6
7
8
820k
R292
0.47
C311
NJM4558M
IC8
1
2
3
4
5
6
7
8
10k
R293
LA4485
IC14
1
CH1IN
2
CH2IN
3
S-GND
4
BTLIN
5
BTLOUT
6
FIL
TER
7
B-VCC
8
S-VCC
9
STBY
10
MUTE
11
CH2OUT
12
B-GND
13
CH1OUT
M62429FP
IC13
1
VIN1
2
VOUT1
3
GND
4
DATA
5
CLK
6
VCC
7
VOUT2
8
VIN2
0.47
C449
1
C353
4.7
R356
CD4094BPWR
IC28
1
STR
2
D
3
CLK
4
Q1
5
Q2
6
Q3
7
Q4
8
GND
9
QS
10
Q’S
11
Q8
12
Q7
13
Q6
14
Q5
15
OE
16
V+
CD4094BPWR
IC27
1
STR
2
D
3
CLK
4
Q1
5
Q2
6
Q3
7
Q4
8
GND
9
QS
10
Q’S
11
Q8
12
Q7
13
Q6
14
Q5
15
OE
16
V+
CD4066BPWR
IC3
1
I/O1
2
O/I1
3
O/I2
4
I/O2
5
CONT2
6
CONT3
7
VSS
8
I/O3
9
O/I3
10
O/I4
11
I/O4
12
CONT4
13
CONT1
14
VDD
CD4066BPWR
IC6
1
I/O1
2
O/I1
3
O/I2
4
I/O2
5
CONT2
6
CONT3
7
VSS
8
I/O3
9
O/I3
10
O/I4
11
I/O4
12
CONT4
13
CONT1
14
VDD
1
C322
KTC4075
Q32
KTC4075
Q31
8.2k
R295
KIA7805API
IC10
I
O
COM
TPC6104
Q61
1
2
3
4
5
6
CD4066BPWR
IC4
1
I/O1
2
O/I1
3
O/I2
4
I/O2
5
CONT2
6
CONT3
7
VSS
8
I/O3
9
O/I3
10
O/I4
11
I/O4
12
CONT4
13
CONT1
14
VDD
10
R294
CD4066BPWR
IC5
1
I/O1
2
O/I1
3
O/I2
4
I/O2
5
CONT2
6
CONT3
7
VSS
8
I/O3
9
O/I3
10
O/I4
11
I/O4
12
CONT4
13
CONT1
14
VDD
10
C235
2.2
C238
2.2
C246
2.2
C263
2.2
C265
10
C291
10
C316
100
C386
KTC4075
Q38
2.2
C248
2.2
C241
2.2
C243
47
R583
0.033
C586
0.22
C582
NJM2211M
IC15
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
10
C585
470
C356
470
C443
LM2904PWR
IC12
1
2
3
4
5
6
7
8
0.0068
C272
0.022
C274
0.0022
C275
0.01
C273
0.0068
C276
0.01
C576
0.01
C579
0.01
C578
0.01
C577
0.01
C581
0.012
C572
0.033
C574
0.033
C573
470p
C575
0.022
C233
0.022
C234
0.0022
C236
560p
C237
0.001
C262
0.01
C251
0.01
C315
0.01
C411
47p
C412
0.01
C385
0.01
C382
0.001
C441
0.01
C331
82p
C347
0.001
C346
0.001
C335
22p
C334
0.01
C350
0.001
C354
47p
C358
47p
C359
470p
C345
470p
C344
0.001
C360
0.001
C361
0.1
C584
0.1
C571
0.1
C271
0.1
C557
0.1
C357
0.1
C232
0.1
C384
0.1
C383
0.22
C264
0.22
C431
2.2
C421
0
R421
47p
C377
470
C355
0.001
C378
2.2
C352
0
R425
2.2
C426
0.01
C307
18k
R271
10k
R273
10k
R274
10k
R275
33k
R272
1k
R276
10k
R277
100k
R572
100k
R571
10k
R573
10k
R574
10k
R575
470k
R581
470k
R580
1.5k
R578
1k
R577
10k
R576
470k
R582
100k
R584
1.8k
R587
15k
R586
39k
R585
1M
R336
1M
R334
1M
R335
15k
R232
470k
R234
33K
R238
33k
R239
2.2k
R240
100k
R245
100k
R246
100k
R242
100k
R244
100k
R241
1M
R248
82k
R317
82k
R316
82k
R315
100k
R313
10k
R323
100k
R309
27k
R312
560k
R308
4.7k
R311
0
R341
1M
R306
1M
R332
1M
R338
1M
R337
1M
R331
1M
R333
100k
R305
47k
R299
100k
R318
100k
R301
27k
R319
1M
R320
1.8k
R321
10k
R302
1M
R250
1M
R251
100k
R252
100k
R253
100k
R258
100k
R259
1M
R256
1M
R254
2.7k
R257
1M
R263
100k
R262
100k
R269
4.7k
R265
1M
R268
1M
R267
1M
R266
18k
R314
100k
R442
47k
R441
560k
R353
15k
R354
33k
R355
33k
R431
0.01
C304
0.22
C317
100
C381
LA4425A
IC9
1
2
3
4
5
100k
R243
0.01
C247
1M
R270
100k
R260
1M
R247
1
C260
100k
R278
2.2
C448
0.001
C293
0.01
C292
0.0068
C323
10k
R325
NTCG16
R324
15k
R326
1
C250
1
C249
0.47
C453
J3
0.01
C589
0.0022
C587
0.1
C588
0.0047
C313
820p
C312
56p
C314
12p
C306
270p
C303
47p
C318
0.1
C301
0.01
C351
0.1
C423
47p
C425
47p
C424
KRC404
Q62
0
R298
2SB1143
Q71
XP6501
Q72
1
2
3
4
5
6
10k
R592
10k
R593
0.001
C332
82P
C348
DSA3A1
D42
0.001
C349
1000
C369
0.1
C370
0.01
C333
22
C591
CP14
CP13
470
R233
0
R423
0
R443
0
R343
0
R344
0
R444
330
R594
330
R595
1k
R596
CP20
CP2
CP7
100
C447
CP11
CP12
680
R264
22k
R231
2.7k
R255
NJM2107F
IC29
1
2
3
4
5
470k
R363
33k
R361
0.47
C556
0.47
C558
0.47
C231
KRA304
Q66
10k
R428
10k
R427
KTC2875
Q65
KIC7W53FK
IC26
1
COM
2
INH
3
VEE
4
GND
5
A
6
CH1
7
CH0
8
VCC
KRA304
Q37
J2
J1
8.2k
R304
47k
R362
100
R429
220k
R235
0.47
C450
390
R236
2.7k
R237
3.3k
R591
1.8k
R261
6.8k
R303
1k
R307
0.1
C302
0.01
C305
J5
J6
J11
J12
100k
R411
18k
R412
0.22
C245
EXTOE
EXTOE
EXTOE
E
V
D
ATA
EVCK
SMIC
SCON
GND
GND
GND
OPTIN
GND
SCK
PCK
to option
SCRAMBLER
unit
to CHASSIS
unit W1
to MAIN
unit J1
to MAIN
unit J2
to LOGIC
board J1
SDATA
PDATA
OPSTB
SCON
OPTIN
OPSTB
MICI
DETI
MICO
DETO
DET70I
DETMI
DETMI
MICOO
MICOO
SAFO
RMUTES
RMUTES
RMUTEM
RMUTEM
RMUTEH
RMUTEH
/PTTC
/PTTC
SMICIN
MMUTES
MMUTES
MMUTEH
MMUTEH
PTTS
PTTS
PTTM
PTTM
VOLO
EXTRXD
ICF3
PTTC
PTTC
WXDEC
WXDEC
DSD70
DSDM
PWRON
EXTTXD
DSC5V
DSC5V
INCOM
INCOM
INCOM
SPMUTE
VO
L
2
MICIM
MICAFO
MICAFO
SCUSE
SCUSE
SCUSE
MICO
DETO
DETI
DETI
SCP
ASS
SCPASS
SCPASS
DETOO
DETOO
PTTM
MMUTES
MMUTEM
MMUTEH
RMUTEM
RMUTES
RMUTEH
H/L
TMUTE
ATT
PCK
PDATA
EXTSTB
FILRMH
FILRMH
FOGIN
FILRMS
SCON
SCPASS
PTTS
SCUSE
FOGC
FOGC
FOG
H/L
H/L
DETM
PCK
PDATA
UNLK
PSTB
PCK
PDATA
UNLK
PSTB
SQL
S5V
DETM
DET70
MOD
GND
GND
GND
TXDET
BPFV
SQL
TXDET
BPFV
TMUTE
ATT
H/L
TMUTE
ATT
H/L
RCV
SEND
DET
DET
FILO
FILO
FILO
MOD
FILRMM
MMIC
MMUTEM
MMUTEM
HAILO
AFMIC
AFMIC
0.001
C336
0.001
C338
47p
C339
47p
C340
47p
C341
0.01
C106
0.01
C107
0.001
C343
0.001
C342
0.01
C330
MIC
MIC
VOL1
MICAF
MICAF
MICAF
GND
GND
PAO-
SP+
SP+
SP-
SP-
HV
VCC
S5V
PWRON
GND
SEND
RCV
GND
VOL1
BEEP
VOL2
FOGC
FOG
EVDATA
EVCK
VOL1
VOL2
FOGC
FOG
EVDATA
EVCK
WXDEC
BPFV
DSDM
SQL
DSD70
TXDET
BPFV
SQL
TXDET
DSCENC
MICG
ICF3
MIC
EXTTXD
EXTRXD
PDATA
UNLK
PCK
PSTB
EXTOE
EXTSTB
OPTIN
OPSTB
MICG
ICF3
MIC
EXTTXD
EXTRXD
PDATA
UNLK
PCK
PSTB
EXTOE
EXTSTB
OPTIN
OPSTB
SP+
SP+
COM12V
COM12V
HAVOLO
DET70
VCC
VCC
VCC
VCC
VCC
HV
HV
J8
HV
J9
GND
HV
FILOS
FILOS
AF5V
AF5V
AF5V
AF5V
AF5V
AF5V
AF5V
AF5V
AF5V
AF5V
AF5V
VBIAS
VBIAS
VBIAS
VBIAS
VBIAS
VBIAS
HAMUTE
S5V
S5V
S5V
S5V
S5V
S5V
S5V
S5V
S5V
S5V
AF UNIT
CP23
VCC
S5V
PAO+
GND
DSCENC
HAVOL
SP-
5V
MICG
EXTTXD
ICF3
EXTRXD
MICG
PTTC
VCC
AF/MIC
GND
SP+
to CHASSIS
unit W1
to CHASSIS
unit W2
to CHASSIS
unit W3
to CHASSIS
unit W3
HAILO+
HAILO-
MICG
4.9V
4.5V
4.8V
2.7V
0.4V
4.2V
0.8V
4.8V
2.7V
13.8V
12.8V
4.9V
13.8V
13.8V
PWR SW
ON 5.0V
OF 0V
4.9V
SQL
OPEN 0.0V
CLOSE 4.9V
4.8V
HAILER PTT ON /RX SP ON 0.0V
HAILER PTT OFF /RX SP OFF 4.7V
11-2 AF UNIT
11 - 2