Icom IC-756PRO III Service Manual page 85

A
B
C
D
R621
2.2k
S622 S621
DS621
(TRANSMIT) (POWER)
CL-200HR
(TIMER)
E
R622 R623 2.2k R624 4.7k R625 15k
6.8k
F
S623 S624 S625 S626
(TUNER) (MONITOR) (NB) (NR)
OFF 4.8V
TUNER ON 0V
MONITOR ON 1.2V
NB ON 2.4V
NR ON 3.7V
OFF 0V
ON 4.7V
Q622 Q623 Q624 Q625
DTC114EE DTC114EE DTC114EE DTC114EE
TNRD
G
H
I
MOND
J
NBD
NRD
R704 R706
(RF/SQL) (NR)
47k 47k
K
R701 R702
R703
RV-308 R705 RV-308
47k
47k
L
(AF) (BAL)
M
N
O
P
Q
R
S
T
R712 R716 R718 R720
R714
EVU-FLAE02B14 EVU-FLAE02B14 EVU-FLAE02B14
EVU-FLAE02B14 EVU-FLAE02B14
(MIC GAIN) (COMP) (BK-IN DELAY)
(RF POWER) (KEY SPEED)
-8V
U
V
W
X
3.0V
3.1V 1.7V
(BIAS CONTROL) (BRIGHT CONTROL) (GAMMA2)
Y
Z
C1404 0.1
C1405 0.1
AA 4.3V
C1406 0.1
SW
GAM1
AB
CPCN
COGC
(GAMMA 1) COMO
BASC
IC1521b
R1541
M5218AFP R1544
10k
5 2.2k
+ 7 CONT1
AC
6
-
R1543 22k LCD CONTRAST
MAX 8.7V
MIN 0.9V
-15V
AD
-18V
AE
+14V
AF
AG
AH
AI
5VF
+14V NOTL R601 47k
PITL R602 47k
PB1A
PB1B
Q901
R904
DTC114EE PB2A
4.7k
MDM2 PB2B
Q905
2SB1201
Q902
R905
DTC114EE
6.8k
MDM1
Q904
2SC4081
PB(1/2)A,PB(1/2)B
D901
Q903 RD5.1M
R906
DTC114EE A 4.8V
right
15k
MDM0
turn
B
R915
10k A
left
turn
LDV B
DS901
R912
CL-200YG
330
DS904 METER BACKLIGHT
R914
CL-200YG MAX 11.9V
330
MIN 5.1V
METER BACK LIGHT
R917 R916
4.7k 2.2k
+
-
+ -
R709
10k
CP401
D701
DAN222
CP402
CP411
MEASUREMENT CONDITIONS
VOLTMETER :50kΩ/VDC CP412
OSCILLOSCOPE :20MHz 1MΩ 25pF
SUPPLY VOLTAGE:13.8V
DISPLAY : 14.1MHz USB
-7.5V DISPLAY BOARD
4.5V
+4R5V
R1526
C1521 0.1 100
C1401 C1409
0.1 0.1
IC1521a
8 M5218AFP
C1408
3
0.1 + 1
C1402
2
0.1 -
4
C1407
0.1
D1201
C1522 R1527
0.1 100 MA8030
C1403
0.1
Q1201
2SA1576
IC1401
M52338FP
1 32
MAIN IN R VCC1
C1110
2 31
CLAMP R EXT IN B 0.1
3 30
MAIN IN G SUB CONT B
4 29
CLAMP G EXT IN G
5 28
MAIN IN B SUB CONT R
6 27
CLAMP B EXT IN R
7 26 GAM2
SW GAM2
8 25 GAM1
HD IN GAM1
9 24 CONT1
CP CONT CONTRAST
10 23 BRGT
VCC2 BRIGHT
11 22
VEE FRP1 IN
12 21
FRP2 IN R OUT
13 20
COM GAIN SUB BIAS R Q1553
14 19
2SA1576
COM OUT G OUT
15 18
BIAS CONT SUB BIAS B
16 17
GND B OUT C1553
10
COMO
Q1554
2SC4081
FRONT
J601 J1
W5
5VF 5VF
NOTL NOTL
R3 47k
PITL PITL
(PITCH)
PB1A PB1A
PB1B PB1B
R1
PB2A PB2A
RV-314
PB2B PB2B
R4 47k
GND
(NOTCH)
GND
GND
2
A
3
B (PBT2)
1
COM
5 S1
A
6
B (PBT1)
4
COM
PBT BOARD
FRONT L1
J941 J1
W3 HF50ACC322513-B
J2
PHE
PHE
AFO 180
PHO R1
L2
PHE
PHE
HF50ACC322513-B
PHNI PHONE
PHNI R2 180
GND
GND
GND
GND
GND
GND
PHONE BOARD
PWRK
FRONT
J921 J1 EP1
W1 J2
DASH
DASH
DOT DOT
EP2
ELEC-KEY
GND
GND
GND
GND
GND
GND
GND
GND
KEY BOARD
J451
SPE
to
MAIN-A unit
Explanatory notes
J352
SSP
CHASSIS
VOLTAGE LINE
J452
P1
TX LINE
SSP SSP
+ SP
RX LINE
SSPE SSPE
-
+14V
R502
R501
-7R5V
1k
HD 15k
POLC
1 14
2 13
C1201 C1211 C1221
3 12
0.1 0.1 0.1 IC542
4 TK16105 11
5 10
6 9
BL
7 8
GL
RL
IC543
SN74CBT3251PWR
D1211 D1221
1 16
MA8030 MA8030
2 15
Q1211 Q1221 3 14
2SA1576 2SA1576
4 13
5 12
6 11
7 10
8 9
IC544
R1551
HCT1G08DCKR
100
1
2
Q1551
2SC4081 3
C549 0.1
IC490
C1554
S-80942CNMC-G9C
10
1
OUT CO
2
VDD
3
VSS NC
R1552
100
Q1552
2SA1576
-15V
+18V
+14V
5VF
J301
LFMD R301 1k LFMD
LMFD R312 1k LMFD
SRES R313 1k SRES
YOBI
R R315 47 R
G R316 47 G
B R317 47 B
HSYNC R318 1k HSYNC
VSYNC R319 1k VSYNC
GND
GND
GND from MAIN-A
unit J891
GND
-8V
-8V
–8V
+18V
+18V
14V
14V
14V
+14V
J321
14V
14V
14V
PHE
PHE
AFO
AFO
PHE
TMD
TMD
PWRK PWRK from MAIN-A
GND unit J861
GND
GND
GND
MICI
8V
MSND
MICE
SQSS SQSS
C323
0.0047
Q321 OFF 4.8V
DTC114EE UP 0.6V
DOWN 1.2V
FRONT
J322 J2
W2
MICI MICI
M8V M8V
MUD MUD MUD
SQLS SQLS
MSND MSND
GND GND
MMICE MMICE
AFO AFO
+18V
C548 0.1
R545
10k
+14V
Q512
2SB1132
5
IC511d
NJM2902V
4 Q511
D512 C513
DTC114EE 12
0.1
RD5.1M
+ 14
13
-
Q513
DTC114EE
5 5
1
4
2 W512
4
12.1V
3 IC511b
4 12.1V
NJM2092V
2
+ 1
3 5
IC492 R511 - + 7
6
10k IC511a
TC4S81F 11 -
NJM2092V
+14V
10 - 2
MIC BOARD
C1
0.0047
J1
7 1
6 8 2
5 3
4
L1 100H
L3 100H
L4 100H
L6
HF50ACC322513-B
C505 0.0047
C506 0.0047
J531
Q514
2SB1132
L5V
HD
VD VD
POLC POLC
Q515 GND
W504
DTC114EE
L5V
RL
to
GL
LCD
BL
unit
VCOM
GND
IC511c W502
NJM2902V
L/R
10 U/D
+ 8
9
- W506
N/P
L18V
-15V
CP5