![background image](http://html.mh-extra.com/html/icom/ic-2820h/ic-2820h_service-manual_612070048.webp)
*; Refer to “PARTS LIST.”
10 - 2
10-2 MAIN UNIT (1)
2SC4738
Q97
R514
22K
Q102
2SC4213
EP63
68K
R764
100K
R784
100
R835
R489
100
C605
47P
10 MSVA
C656
47K
R851
1
C867
MMZ1005Y102CT
EP31
C647
0.0033
R635
330K
10
C697
M
PZ1608S221A
EP60
0.022
C639
R493
100
C654
0.
1
*D128
EP27
TC7W53FU
IC61
1
COM
2
INH
3
VEE
4
GND
5
A
6
CH1
7
CH0
8
VCC
220K
R768
C663
10
0.01
C596
R567
4.7K
1M
R589
390K
R823
EP29
MMZ1005Y102CT
EP68
EP41
220K
R878
47K
R819
2.2 MSVA
C625
1
2
MMZ1608Y102BT
EP14
10K
R867
EP11
27K
R609
220K
R765
C711
470
M PZ1608S221A
EP54
CTH30V222S15A
C847
CD4066BPWR
IC30
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
1M
R820
C
719
47P
C691
0.001
C578
0
.47
C704
470P
C641
0.001
C581
47P
47K
R618
C714
100
J7
B2B-ZR-SM4-TF
1
2
3
4
100K
R816
0.039
C620
100K
R868
R590
2.2M
22P
C662
C701
0.
1
100
R759
100K
R783
R643
15K
R665
12K
C636
1
C684 10
0.001
C899
100K
R780
R484
100K
TA7805F
IC21
I
O
G
0.47
C943
0.01
C907
C591
0.001
0.001
C919
1
C653
TC7W53FU
IC58
1
COM
2
INH
3
VEE
4
GND
5
A
6
CH1
7
CH0
8
VCC
R645
39K
C700
47
C673
0.001
R649
8.2K
R626
47K
MMZ1005Y102CT
EP
1
8
LMV358IPW
IC49
1
2
3
4
5
6
7
8
*D138
SP1
Q93
UNR9213J
R494
4.7K
E
P36
R563
100
C579
2200
MMZ1608Y102BT
EP13
J8
PJ-3047S
ZBFS5105
L139
R499
470
ZBFS5105
L141
R498
4.7K
C717
100P
R637
15K
0.001
C909
R586
22K
2.2M
R796
470
R772
220K
R767
10
C687
1SS400
D168
R641
100K
R497
4.7K
TC7W53FU
IC57
1
COM
2
INH
3
VEE
4
GND
5
A
6
CH1
7
CH0
8
VCC
2.2K
R802
*R883
220K
R879
R511
100
R582
2.2M
M
PZ1608S221A
EP59
TC7W53FU
IC37
1
COM
2
INH
3
VEE
4
GND
5
A
6
CH1
7
CH0
8
VCC
1
C644
18K
R804
390K
R827
0.022
C659
ZBFS5105
L140
R658
390
C652
0.
1
100
R825
0.001
C676
0.22
C851
*D127
0.1
C623
4.
7
C863
0.
1
C917
HD64F2506RFC26DV
IC25
1
PE5/D5
2
PE6/D6
3
PE7/D7
4
PD0/D8
5
PD1/D9
6
PD2/D10
7
PD3/D11
8
PD4/D12
9
PD5/D13
10
PD6/D14
11
PD7/D15
12
Vss
13
PC0/A0
14
P1Vcc
15
PC1/A1
16
PC2/A2
17
PC3/A3
18
PC4/A4
19
PC5/A5
20
PC6/A6
21
PC7/A7
22
PB0/A8
23
PB1/A9
24
PB2/A10
25
PB3/A11
26
PB4/A12
27
PB5/A13
28
PB6/A14
29
PB7/A15
30
PA0/A16
31
PA1/A17
32
PA2/A18
33
PA3/A19
34
PA4/A20
35
PA5/A21
36
PA6/A22
37
PA7/A23
38
PH7
39
PH6
40
PH5
41
PH4
42
PH3
43
PH2
44
PH1
45
PH0
46
PJ7
47
PJ6
48
PJ5
49
PJ4
50
PJ3
51
PJ2
52
PJ1
53
PJ0
54
Vss
55
P97/AN15/DA1
56
P96/AN14/DA0
57
P
95/AN13
58
P
94/AN12
59
P
93/AN11
60
P
92/AN10
61
P91/AN9
62
P90/AN8
63
P47/AN7
64
P46/AN6
65
P45/AN5
66
P44/AN4
67
AVss
68
P43/AN3
69
P42/AN2
70
P41/AN1
71
P40/AN0
72
Vref
73
AVcc
74
P50/TxD2
75
P51/RxD2
76
P52/SCK2
77
PF0/BREQ/IRQ2
78
PF1/BACK/BUZZ
79
PF2/WAIT
80
PF3/LWR/ADTRG/IRQ3
81
PF4/HWR
82
PF5/RD
83
PF6/AS
84
P1Vcc
85
PF7/FAI
86
Vss
87
TEST
88
VCL*
89
OSC2
90
OSC1
91
NMI
92
MD2
93
XTAL
94
Vss
95
EXTAL
96
Vcc
97
MD0
98
MD1
99
STBY
100
RES
101
P20/TIOCA3
102
P21/TIOCB3
103
P22/TIOCC3
104
P23/TIOCD3
105
P24/TIOCA4
106
P25/TIOCB4
107
P26/TIOCA5
108
P27/TIOCB5
109
P17/TIOCB2/TCLK
D
110
P16/TIOCA2/IRQ1
111
P15/TIOCB1/TCLKC
112
P14/TIOCA1/IRQ0
113
P13/TIOCD0/TCLKB
114
P12/TIOCC0/TCLK
A
115
P11/TIOCB0
116
P10/TIOCA0
117
Vss
118
P2Vcc
119
P37/TxD4
120
P36/RxD
4
121
P35/SCK1/SCK4/SCL0/IRQ
5
122
P34/RxD1/SDA0
123
P33/TxD1/SCL1
124
P32/SCK0/SDA1/IRQ4
125
P31/RxD
0
126
P30/TxD0
127
P77/TxD3
128
P76/RxD
3
129
P75/TMO3/SCK3
130
P74/TMO2/MRES
131
P73/TMO1/CS7
132
P72/TMO0/CS6
133
P71/TMRI23/TMCI23/CS5
134
P70/TMRI01/TMCI01/CS4
135
PG4/CS0
136
PG3/CS1
137
PG2/CS2
138
PG1/CS3/IRQ7
139
PG0/IRQ
6
140
PE0/D
0
141
PE1/D
1
142
PE2/D
2
143
PE3/D
3
144
PE4/D
4
0.001
C628
C640
0.
1
0.
1
C911
*D125
470K
R859
3.9K
R822
10K
R781
100
R831
C677
0.
1
C606
0.47
EP42
C709
470
R572
100K
10K
R866
MA2S111
D164
R539
100
R663
330K
C650
10
R556
100
10
C722
C683
0.033
*D133
1
C624
Q81
2SB1132
VDET
100
R813
R530
470K
C616
0.
1
LM2902PWR
IC48
1
2
3
4
5
6
7 8
9
10
11
12
13
14
EP9
470P
C669
390P
C855
EP7
0.0039
C856
EP57
0.1
C903
R647
100K
*D137
Q84
2SA1588
MMZ1005Y102CT
EP70
22K
R763
Q 103
2SC4213
0.0033
C643
EP39
Q82
UNR9214J
8V
100K
R592
C603
0.001
R536
100
5V
0.1
C645
1
C859
0.22
C849
R570
100K
*D131
R515
10K
EP3
0
R521
330K
C602
0.
1
47K
R863
1.8K
R578
*D126
UAFO
0.
1
C898
R524
10K
18P
C588
R479
1k
C679
0.1
1M
R862
R540
100
C706
47
TC7W53FU
IC51
1
COM
2
INH
3
VEE
4
GND
5
A
6
CH1
7
CH0
8
VCC
0.001
C925
C707
100
R664
100K
R519
100K
C580
0.
1
Q98
U NR9210J
R659
4.
7
D122
MA8047
5.6K
R575
S-80945CNMC
IC23
1
OUT
2
VDD
3
VSS
4
NC
5
CD
4.7
C865
2SA1362
Q94
EP2
5
27K
R613
10
C611
100K
R815
22K
R872
47P
C902
0.001
C629
R495
1k
47K
R818
180K
R850
C601 0.001
CD4066BPWR
IC35
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
C586
10
MMZ1005Y102CT
EP51
C590
0.
1
R614
2.2M
R588
8.2K
0.039
C619
*D132
0.001
C674
47K
R861
J9
HSJ1403-01-010
100
R836
100K
R573
0.
1
C670
R660
100K
R510
39K
0.01
C910
0.022
C666
R616
10K
100
R833
4.
7
C661
C678
10
C680
0.1
R638
10K
0.001
C908
330K
R769
C642
0.001
HVC376B
D161
R628
100K
390K
R880
47K
R864
0.22
C852
D121
MA2S111
0.01
C585
HSJ1462-01-010
J5
C703
220
2SB798
Q96
C688
0.47
CD4066BPWR
IC31
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
EP61
C607
47P
*D134
J6
AXN330C130P
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
C604
22P
C610
0.
1
C712
0.
1
Q87
2SC4738
220K
R798
EP10
M
PZ1608S221A
E
P50
15K
R787
MMZ1005Y102CT
EP24
47K
R860
R594
4.7K
R527
4.7K
C621
33 MSVB2
R525
100
TA7808F
IC24
I O
G
R557
100
M
PZ1608S221A
EP55
10K
R612
R545
15K
0.
1
C649
LMV321IDCK
IC50
1
2
3
4
5
10
C658
1SS400
D166
C617
0.
1
MMZ1608Y102BT X8
EP5
R534
100
EP34
1SS400
D167
0.001
C618
0
R579
0.1
C648
R642
100K
2.2K
R785
R532
33K
R644
10K
MMZ1005Y102CT
EP32
C599
4P
D140
DA221
R533
68K
R632
39K
Q83
2SA1588
0.
1
C906
5VS
470P
C675
52465-1071
J24
12
34
56
78
91
0
R475
22K
VAFO
R547
22K
MAX3221IPWR
IC46
1
EN
2
C1+
3
V+
4
C1-
5
C2+
6
C2-
7
V-
8
RIN
9
ROUT
10
INVALID
11
DI N
12
FORCEO N
13
COUT
14
GND
15
VCC
16
FORCEOFF
100K
R829
220K
R797
0.068
C860
R523
12K
R476
4.7K
470K
R775
R559
100
100
R838
R485
1.5K
R477
47K
47K
R817
CF20OPEN
CP1
ZBFS5105
L138
D142
MA742
27K
R611
R558
100
10K
R608
C597
0.001
100
R508
HVC376B
D162
R631
330K
C689
0.47
220K
R779
HV
R583
2.2M
UMG9N
Q99
1
2
3
4
5
0.
1
C914
R483
1
ZXCT1022
IC55
1
NC
2
GND
3
VOUT
4
VIN
5
LOAD
1
C651
100
R814
TA75S558F
IC28
1
2
3
4
5
R653
390
0.033
C866
0.
1
C904
24LC512T
IC22
1
A0
2
A1
3
A2
4
VSS
5
SDA
6
SCL
7
WP
8
VCC
15K
R821
R537
100
R624
100
Q90
UNR9213J
C627
0.01
220K
R799
R554
100
X4
CR-841
E
P35
4.7
C864
R571
47K
R560
18K
0.001
C626
R562
470K
R517
2.2K
R568
100K
R518
10
0
*D124
*D130
EP8
R561
100
0.01
C638
C593
47P
10K
R577
0.01
C944
R522
120K
1SS400
D165
C694
0.47
15K
R774
E
P40
680
R593
0.001
C672
D119
MA2S111
Q86
2SC4738
C692
0.068
0.001
C708
0.047
C862
C718
220
R478
22K
C646
0.
1
C598
0.001
Q95
U NR9213J
0.01
C698
10
C695
3.3K
R617
R486
100
*D129
E
P33
EP62
10K
R865
3008L-8P8C
J2
1
2
3
4
5
6
7
8
C589
0.001
100
R516
1M
R621
J3
PCB-606
1
1
2
2
3
3
4
4
5
5
6
6
M PZ1608S221A
EP52
0.
1
C905
R501
470
MMZ1005Y102CT
EP19
AN6123MS
IC32
1
VCC
2
DET
3
INPUT
4
GND
5
OUTPUT
EP64
D117
RD20E
R581
100K
EP58
390K
R882
*D135
R587
22K
R500
4.7K
C594
68P
10
R801
1k
R789
C600
0.033
1k
R473
C655
0.
1
R504
100
0.001
C836
Q100
UNR9213J
2.2 MSVA
C584
L5V
CR-838
X6
0.001
C924
Q92
UNR9113J
8.2K
R574
100P
C857
2.2M
R615
0.001
C913
MMZ1005Y102CT
MMZ1005Y102CT
EP26
C897
0.001
0.001
C657
100K
R871
C592
0.001
DAFOUT
10K
R610
R553
100
220
C948
R585
2.2M
0.01
C668
0.
1
C918
100
R812
220K
R766
R541
27K
C637
1
UDET
MMZ1005Y102CT
EP16
C716
0.1
R598
2.2M
1
C873
TC7W53FU
IC34
1
COM
2
INH
3
VEE
4
GND
5
A
6
CH1
7
CH0
8
VCC
10U
L163
220K
R771
100
C665
100
R839
10K
R788
22P
C660
R584
2.2M
0.001
C622
R627
3.9K
0.001
C900
D120
MA2S111
R480
47K
C705
10
470
R619
*D139
470P
C664
LA4445
IC38
1
1
2
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
10
10
11
11
12
12
R625
47K
E
P66
R509
NTCG10
220K
R762
TC7W53FU
IC29
1
COM
2
INH
3
VEE
4
GND
5
A
6
CH1
7
CH0
8
VCC
100
R830
Q101
2SC4213
R506
10K
C613
10
R490
10K
0.
1
C915
220K
R770
MMZ1005Y102CT
EP69
R639
1k
C685 10
R591
2.2M
0.001
C635
E
P38
0.
1
C630
Q88
UNR9213J
R661
4.
7
R549
0
EP6
M PZ1608S221A
EP53
D118
DSA3A1
TC7W53FU
IC60
1
COM
2
INH
3
VEE
4
GND
5
A
6
CH1
7
CH0
8
VCC
MMZ1005Y102CT
EP20
10
C872
100P
C858
MA2S111
D141
100K
R782
*D136
10K
R620
MPZ1608S221A
EP49
R512
100
0
R828
BU8872FS
IC56
1
INPUT
2
NC
3
O SC0
4
NC
5
NC
6
OSCI
7
NC
8
GND
9
SD
10
NC
11
ACK
12
NC
13
NC
14
EST
15
NC
16
VDD
OPC-465
W50
100
R758
Q91
UNR9213J
MMZ1005Y102CT
EP23
R623
15K
0.0056
C861
R552
100
C710
0.
1
0.22
C850
470K
R858
C614
0.
1
R550
1.2K
R482
10K
100
R832
EP12
47P
C901
390K
R786
R481
1M
R564
100
10
C667
220K
R777
R640
5.6K
LMV321IDCK
IC26
1
2
3
4
5
R630
330K
TC7W53FU
IC52
1
COM
2
INH
3
VEE
4
GND
5
A
6
CH1
7
CH0
8
VCC
0.
1
C916
EP37
R569
100K
J4
DN-508B-6-L
1
2
3
4
5
6
R529
1k
390K
R881
10
C612
R520
100
R538
4.7K
2.7K
R773
R566
8.2K
E
P43
TC4S66
F
IC59
1
2
3
4
5
220K
R778
220K
R800
EP56
0.
1
C934
SM6451B
IC33
1
RSTN
2
ADRS1
3
ADRS2
4
DVDD
5
LOUT
6
LIN
7
AVDD
8
VRL
9
VRR
10
AVSS
11
RIN
12
ROUT
13
DVSS
14
MLEN
15
MCK
16
MDT
390K
R826
SN74AHC1G08DCK3
IC36
1
2
3
4
5
R600
2.2M
UNR9213J
Q118
P_PTT
DADJSEL
P_SQL
VAFO
GPSRXD0
GPSTXD0
SUB_SEL
98_DATA
R_DET_MUTE
R_DA_SEL
L_WXALT
L_DTCS_IN
R_WN_SEL
L_DA_SEL
L_DET_MUTE
L_WN_SEL
R400_S
R_RX800
R_R5C
L_R5C
R_AMC
L_AMC
R_UNLOCK
L_UNLOCK
R_PLLSW
L_PLLSW
R_PLLSTB
L_PLLSTB
PLLCK
PLLDATA
L_VCO_SHIFT
UMMUT E
VMMUTE
R_UVCO_SEL
R_VVCO_SEL
L_LO_SW
DA_DATA
DA_CK
DA_STB
MOD_DA
MODSEL
DDETMUTE
AF_VOL_STB
AF_VOL_CK
AF_VOL_DATA
AF_VOL_RES
L_AF_MUTE
DTCS
R_AF_MUTE
D
TCS_SEL
DADJMUTE
VCC
AMBERES
AMBEEPR
AMBESTB
AMBECL
K
BTONE
TXDT
TXCK
DCEL
AMBERXD
RXCK
GPSBOOT
DVC
AMBETXD
ACQ
R
XDT
GPSRESET
DMOD
C5V
C5V
DDETSEL
L_AFFILSEL
R_AFFILSEL
AN
DA_SEL
DA2_STB
DA3_STB
R_DTCS_I
N
L_DTCS_IN
L_WXALT
R_WXALT
DTMSTB
L_RSLV
MICU/
D
MICUD
GPSOPT
HV
P_LR_SEL
SUB_SEL
RPT_MUTE
GPSRXD0
R_DATA
TX_DATA
MIC_SEL
XOUT
GPSRESET
DCEL
ACQ
SCL
SDA
AMBECL
K
TX232
RX232
DA_STB
R_AF_MUT
E
L_AFFILSE
L
GPSBOOT
R2
R1
D5VC
DA3_STB
R_DET_MUTE
R_AFFILSEL
R
_DA_SE
L
L_LO_SW
R_VVCO_SEL
R_UVCO_SE
L
P_MOD_MUTE
MODSEL
MOD_DA
AN
DA_SEL
MM_MUTE
DCONT
RX232
G
PSTXD0
AMBEEPR
AMBESTB
DDETMUTE
8V
CLONE_OUT
RESET
UAFO
DTMFSEL
DTMSD
DTMCK
DTMSTB
R_WXALT
R_DTCS_IN
L_SQL
L_RSSI
R_SQL
R_RSSI
L_DA_SEL
L_DET_MUTE
DVDTMFSEL
DAFOUT
MIC_PTT
P_LR_SEL
TXDT
T
XCK
RXDT
RXCK
AMBERES
DADJMUTE
DTCS
DTMF
M
IC_SEL
TEMP
MD2
XI
N
AF_VOL_CK
AF_VOL_DATA
L_AF_MUTE
AF_VOL_RES
CLONE_IN
RPT_MUTE
1200_9600SEL
MM_MUTE
DTMFSEL
DVDTMFSEL
DCONT
P_SQL
1200_9600SEL
R_WN_SEL
P_PTT
OP+5V
D5VC
MIC_SENC
M IC_SENC
DDETSEL
CLONE_I
N
CLONE_OUT
L_AMC
L_PLLSTB
ANALOGSW
R_PLLSTB
DTCS_SEL
L_R5C
L_WN_SEL
UMMUT E
UTX_C
L_VCO_SHIFT
R_PLLSW
R_UNLOCK
PLLCK
PLLDATA
L_UNLOCK
VMMUTE
VTX_C
AF_VOL_STB
PWR
TX232
DA_CK
DA_DAT
A
DA2_STB
R_AMC
R_R5C
R400_S
R_RX800
CL_SFT1
AMOD
UTX_C
UTX_C
R_LV
R_RSSI
R_RSLV
L_RSLV
VTX_C
L_RSSI
L_LV
L_LV
R_LV
R_SQL
98_DATA
DTMCK
DTMS
D
DVC
L_DET_MUTE
L_DA_SEL
R_DET_MUTE
R_AFFILSEL
R_DA_SEL
R_DA_SEL
L_LO_SW
L_LO_SW
R_VVCO_SEL
R_VVCO_SEL
L
_PLLSW
R_UVCO_SEL
R_UVCO_SEL
P_MOD_MUTE
AMBERXD
AMBETX
D
ICUTX
ICURX
ICUSCK
CL_SFT1
CL_SFT2
L_SQL
CL_SFT2
RESET
MIC_PTT
MIC_PTT
NMI
NMI
MD2
RESET
R_RSL
V
MICUD
T
X_DAT
A
R_DATA
5V
R2
R1
DTMF
5VS
G
PSOPT
ICURX
ICUSCK
ICUTX
IDET
DADJSEL
A
NALOGS
W
CPU5
V
8V
GND
CTHV
MICU/D
MIC
EXTMIC
GND
PTT
MICIN
MICE
D
ATAIN
AFOUT
DATAOUT
MRIPT
HV
CPU DTMF
m
ini RIP
9600bps
D-star
1/2 VCC
VDET
UDET
CTCSS/DTCS
RDATA
TXDATA
To the CONTROL UNIT
ICU and Flash
C;4.95V
C;7.88V
C;4.86V
C;4.87V