Icom IC-M304 Service Manual page 26

SECTION 11 VOLTAGE DIAGRAM
• LOGIC UNIT
DIM MAX:12.27V
Q2
KTA1664
Q4 Q3
KTC4075
IC2
R35
220
NMEA+ PC357N6J000F
1
NMEA-
2
ICF3
3
4
ICF3
CP7
J2
CP10S
B4B-ZR-SM4-TF
KDS122
C18
0.01
IC4
1
A0 VCC
2
A1 WP
3
A2 SCL
4
VSS SDA
HN58X2464TI
• VR UNIT
R1
10k J1
HV
5
GND
4
VOL2
3
VOL1
2
HVS
1
• SQL UNIT
R1
10k J1
GND
3
SQLV
2
SQLI
1
R21
27
R22
27
R23
KTC4075
27
3.31V
R24
39K
KEYM
IC3 TXDET
1 5 SQLV
2
3 4 PCK
PDATA
WXDEC
TC7S14FU
CP4
D3
BEEP
R37
CP10S
PSTB
15K
Q6
DTC114TU
R38
1K
DSCDEC
UNLK
8
7
6
5
IC5
1 5
OUT CD
2
VDD
3 4
VSS NC
S-80942CNMC
11 - 1
5V
1
P67/AN7
2
P66/AN6
3
P65/AN5
4
P64/AN4
5
P63/SCLK22/AN3
6
P62/SCLK21/AN2
7
P61/SOUT2/AN1
8
P60/SIN2/AN0
9
P57/ADT/DA2
10
P56/DA1
11
P55/CNTR1
12 IC1
P54/CNTR0
13 M37560EFGP
P53/RTP1
14
P52/RTP0
15
P51/PWM1
16
P50/PWM0
17
P47/SRDY1
18
P46/SCLK 1
19
P45/TXD
20
P44/RXD
21
P43/TOUR
22
P42/INT2
23
P41/INT1
24
P40
25
P77
R61
100K
R62
R54
10K
6.8K
R65
1M
X1
S1 S2 S3
CR-834
SCAN CH/WX CH1 6 DN
R : 6 . 8 5 V
R67
0
DS1
SDT-DM2360
SP+
J1
30
BEE P
28
SQLV
26
24
75
SEG6 5V
SEG13 22
74
SEG18 WXDEC
SEG14 20
73
SEG19 DSCDEC
SEG15 18
72 SEG20 RCV
SEG16 16
71 SEG3 SEND
14
SEG17
70 SEG21 TMUTE
12
P30/SEG18
69 SEG22 TXDET
P31/SEG19 10
68 SEG23 H/ L
P32/SEG20 8
67 SEG2 PSTB
P33/SEG21 6
66 SEG24 PDATA
P34/SEG22 4
65 SEG25
P35/SEG23 2
64 SEG26
P36/SEG24
63 SEG1 30FLT-SM2-TB
P37/SEG25
62 SEG12
P00/SEG26
61 SEG27 GND
P01/SEG27
60
P02/SEG28
59
P03/SEG29
58
P04/SEG30
57
P05/SEG31
56
P06/SEG32
55
P07/SEG33
54
BPLV L
P10/SEG34
53
RCV
P11/SEG35
52
SEND
P12/SEG36
51
TMUTE
P13/SEG37
RMUTE
H/ L
SQLC
PTTC
0.46V
S4 S5 S6 S7
UP DSC DTRS
0V
7.9872MHz
CP10S
HVS
CP5
CP10S
5V
CP6
SP-
29
BPLVL
27
HVS
25
5V
23
DSCENC
21
RMUTE
19
PTTC
17
PTT
15
KEYM
13
SQL
11
SQLC
9
BPF
7
PCK
5
UNLK
3
1