Front Unit - Icom IC-756PROII Service Manual

SECTION 10 VOLTAGE DIAGRAMS

10-1 FRONT UNIT

MAIN DIAL UP MAIN DIAL DOWN
M UP 4.6V
M DN 4.6V
S1
EVQ-VCJF0324B FRONT
J1 W4
RUP
UP
5VF
E
RDN
DN
RIT DIAL UP RIT DIAL DOWN
RSA 4.8V
RIT BOARD
RSB 4.8V
FRONT
J1
W6
F5K
F4K
F3K
MODE BOARD
F2K
F1K
S1 S2 S3 S4 S5 SPEK
EXTK
FILK
(F-1) (F-2) (F-3) (F-4) (F-5)
AMK
CWK
SSBK
KI2
KI1
S6 S7 S8 S9 S10 S11 5VF
(SSB) (CW/RTTY) (AM/FM) (FILTER) (EXIT) (SPEECH)
R1 R2 R3 R4 R5 R6 R7
6.8k 2.2k 4.7k 15k 6.8k 2.2k 4.7k
S12 S13 S14 S15 S16 S17 S18
(A) (B) (C) (D) (E) (F) (G)
C2 0.1
FRONT
J1
W7
SPLK
1K
3K
7K
10K
S1 S6 S10 S14 S18 S24
14K
SPLK 1K 3K 7K MUPK PBTK 18K
21K
(SPLIT) (1.8) (3.5) (7) (UP) (PBT-CL)
24K
S2 S7 S11 S15 S19 S25 28K
10K 14K 18K MDNK NOTK 50K
GENK
(DW) (10) (14) (18) (DOWN) (NOTCH)
FINK
S3 S8 S12 S16 S20 S26 MPWK
21K 24K 28K MWK MPRK
(CHANGE) (21) (24) (28) (MW) (RIT)
S4 S9 S13 S17 S21 S27
GENK 50K FINK MCLK
FRONT
J2
(V/M) (GENE) (50) (F-INP) (M-CL) ( TX) W8
MUPK
S5 S22 S28
MDNK
TSK MWK
MCLK
(M/S) (TS) (CLEAR)
TSK
S29 S30 S23 XFCK
MPWK MPRK XFCK LOCK
PBTK
(MP-W) (MP-R) (XFC)
NOTK
S31 KI4
LOCK 5VF
KI3
(LOCK)
LDV
LOCD
TXD
RXD
NOTD
PBTD
Q1 DS1 Q4 DS4
DTC114EE R8 CL-200HR DTC114EE R11 CL-220YG
5.6k 1k
(LOCK) LED (NOTCH) LED
Q2 DS2 Q5 DS5
DTC114EE R9 CL-200HR DTC114EE R12 CL-220YG
ON 4.5V
5.6k 1k
OFF 0V
(TX) LED (TWIN PEAK FILTER) LED
Q3 DS3
to
DTC114EE R10 CL-220YG
680 ON 4.5V LCD
OFF 0V
(RX) LED
to
LCD
TEN-KEY BOARD
10 - 1
CP101
J101
5VF
CP102 CP103
MUP IC101a IC101c
µPD4030BG µPD4030BG
MDN
GND 14 8
R124 1M 1 10
3 9
2
R122 R123 14
R102 1
220k 100k 8 7 MSA
CP104 10 15k
2 C406
9 IC102a
3 10
R104 7 MC14071BFEL
IC102c 47k 5
MC14071BFEL 5 4 C405
J120 4 6
R128 1M 6 0.1 4.8V
RUP
IC101b
5VF R126 R127
µPD4030BG
220k 100k IC102b 0.1µS
RDN 12 11 MC14071BFEL
GND 13
GND 12
11 1.5V
IC102d
GND 13
MC14071BFEL
GND
R103 IC101d
GND
15k µPD4030BG
GND
GND
AS0 1
PC3/AN11
5VF 2
AVSS
3
C401 X401 TEST
4
12p CR-567 X2
5
J201
X1
R201 1k F5K 6
C402 VSS
R202 1k F4K 7
12p OSC1
F3K 8
R203 1k
OSC2
R204 1k F2K 9
RES
R205 1k F1K 10
MDO
SPEK ASL0 11
R206 1k
P20/IRQ4/ADTRG
R207 1k EXTK MSB 12
P21/UD
R208 1k FILK IC411 ASL1 13 IC401
P22
AMK BU4051BCFV ASL2 14 HD6433832SD66H
R209 1k P23
R210 1k CWK 1 16 F1K 15
X4 VDD P24
R211 1k SSBK 2 15 F2K 16
X6 X2 R402 P25
KI2 3 14 F3K 17
X X1 1k P26
KI1 4 13 F4K 18
X7 X0 P27
5VF 5 12 F5K 19
X5 X3 P30/SCK1
GND 6 11 SSBK 20
INH A P31/SI1
GND 7 10 CWK 21
VEE B P32/SO1
8 9 AMK 22
OFF 4.8V VSS C P33/SCK2
KI4 FILK 23
A 0V P34/SI2
EXTK 24
B 1.2V
OFF 4.8V P35/SO2
C 2.4V KI3 SRES SPEK 25
E 0V D 3.7V P36/STRB
F 1.2V
G 2.4V
MUDK
DASH
DOT
D421 D423
DAN222 DAN222
SPLK
5VF
R404 47k
J221 R405 47k
D422
R221 1k SPLK R406 47k
DAN222
1K DOTK
R222 1k R407 47k
R223 1k 3K DSHK
R224 1k 7K
R225 1k 10K D425 D424
DAN222 DAN222
R226 1k 14K
R227 1k 18K
R228 1k 21K
24K
R229 1k
IC881 IC501
R230 1k 28K
R881 TA79LO8F TA79LO8F
R231 1k 50K
56
GENK MUD
R232 1k
D431 I O I O
R233 1k FINK
DAN222 R882 G G
R234 1k MPWK
56
MPRK
R235 1k
GND
OFF 4.8V
RIT 0V
∆TX 1.2V
CLEAR 2.4V D432
J241
DAN222
R241 1k MUPK
R242 1k MDNK
R243 1k MWK
R244 1k MCLK
D821 1SS322
R245 1k TSK
18.6V
R246 1k XFCK
R821
R247 1k LOCK IC861 Q821 L823 IC821
TA7805F 2SC4081 1000µH 1.2k
R861 BA6161F L822
R248 1k PBTK
12 NLFC565050T-472K
R249 1k NOTK 8 1
I O R824
R250 1k KI4 7 2
G 10k
5VF R862 6 3
12
R251 1k KI3 5 4
LDV
R252 1k LOCD R863
12
R253 1k TXD
R254 1k RXD
R255 1k NOTD
R256 1k PBTD
GND +14V
GND 5VF R850 330
GND Q841 IC841
GND 2SB1124S R848 470 NJM2360M
GND L801 1 8
OFF 4.8V 100µH Q802 CS CD
2SB1201 LCD BACKLIGHT
GND DUAL WATCH 0V R849 470 2 7
MAX 4.8V ES SI
CHANGE 1.2V Q801 3 6
MIN 0V CT V+
VFO/MEMO 2.4V 2SC4081 L843 4 5
C843 GND INVIN
MAIN/SUB 3.7V R801 D10F-A814AY-101K
330p
33k
L803 R845
L802 D801
D818HN-1107 1.2k
J801 D10F-A814AY-101K RD3.0M D841
RB050L-40
CFL+
-15.4V
Q805
C805 L842
DTC114EE SLF12565T-680M2R0
J802 15p
CFL- -15V
+18V
W801
Q804 Q803 +14V
2SC3647 2SC3647 5VF
5VF
+14V
R621
Q901
S622 S621 2.2k R904
DS621 DTC114EE
(TRANSMIT) (POWER) 4.7k
CL-200HR MDM2
R441 10k L401
R442 47k HF50ACC322513-B
R443 47k (TIMER)
R444 10k
R622 R623 2.2k R624 4.7k R625 15k
R445 10k 6.8k Q902
R905
R446 10k KIO DTC114EE
6.8k
MDM1
S623 S624 S625 S626
(TUNER) (MONITOR) (NB) (NR)
OFF 4.8V
TUNER ON 0V Q903
R906
MONITOR ON 1.2V DTC114EE
15k
NB ON 2.4V MDM0
CP400
NR ON 3.7V
75 NOTD
P97/SEG40/CL1
74 PBTD LDV
P96/SEG39/CL2 OFF 0V
73 RXD
P95/SEG38/D0 ON 4.7V
72 TXD Q622 Q623 Q624 Q625
P94/SEG37/M
71 LOCD DTC114EE DTC114EE DTC114EE DTC114EE
P93/SEG36
70 NRD TNRD
P92/SEG35
69 NBD
P91/SEG34
68 MOND
P90/SEG33
67 TNRD MOND
P87/SEG32
66 MDM2 NBD
P86/SEG31
65 MDM1 NRD
P85/SEG30
64 MDN0
P84/SEG29
63 BKLS
P83/SEG28
62 HDD2 R704 R706
P82/SEG27 (RF/SQL) (NR)
47k 47k
61 HDD1 RFL
P81/SEG26
60 HDD0
P80/SEG25
59 MAT1
P77/SEG24
58 PHNI R701 R702
P76/SEG23 R703
57 DSHK RV-308 R705 RV-308
P75/SEG22 47k
56 DOTK AFL 47k
P74/SEG21
R917 R916
55 TRAK
P73/SEG20 4.7k 2.2k
54 NOTK
P72/SEG19 (AF) (BAL)
53 PBTK
P71/SEG18
52 LOCK NRL
P70/SEG17
51 XFCK BALL
P67/SEG16
5VF
DELL
KYSL
CMPL
PWRL R709
10k
MIGL
R712 R716 R720
R714 R718
EVU-FLAE02B14 EVU-FLAE02B14 EVU-FLAE02B14
EVU-FLAE02B14 EVU-FLAE02B14
(MIC GAIN) (RF POWER) (COMP) (KEY SPEED) (BK-IN DELAY)
–8V
CNTV
+14V
-7.5V
D501 4.5V
1SS322
-7R5V
+4R5V
3.0V
3.1V 1.7V
C1401
0.1
C1402
0.1
(INPUT SELECT) (BIAS CONTROL) (BRIGHT CONTROL) (GAMMA2)
CPCN
IC1401
M52338FP
1.3V
L821 1
HF50ACC322413-B MAIN IN R VCC1
C1404 0.1 2
CLAMP R EXT IN B
3
MAIN IN G SUB CONT B
(CLAMP CONTROL) 4
C1405 0.1
4.3V CLAMP G EXT IN G
5
MAIN IN B SUB CONT R
C1406 0.1 6
CLAMP B EXT IN R
SW 7
SW GAM2
COGC GAM1 8
HD IN GAM1
CPCN 9
CP CONT CONTRAST
10
1.6V VCC2 BRIGHT
11
VEE FRP1 IN
12
FRP2 IN R OUT
COGC 13
COM GAIN SUB BIAS R
(COMMON GAIN) (GAMMA 1) COMO 14
COM OUT G OUT
IC1521b BASC 15
BIAS CONT SUB BIAS B
R1541 M5218AFP 16
10k R1544 GND B OUT
L841 CNTV
5 2.2k
D10F-A814AY-101K + 7 CONT1
6
-
R1543 22k LCD CONTRAST
MAX 8.7V
MIN 0.9V
FRONT
J601 J1
W5
5VF 5VF
NOTL R601 47k NOTL NOTL
R3 47k
PITL R602 47k PITL PITL
(PITCH)
PB1A PB1A PB1A
PB1B PB1B PB1B
R1
PB2A PB2A PB2A
RV-314
Q905 PB2B PB2B PB2B
2SB1201 GND R4 47k
(NOTCH)
GND
GND
2
A
3
Q904
2SC4081 B (PBT2)
1
COM
5 S1
A
PB(1/2)A,PB(1/2)B 6
D901 B (PBT1)
RD5.1M 4
COM
A 4.8V
right
PBT BOARD
turn B
R915
10k A
left
turn
B
FRONT L1
J941 J1
W3 HF50ACC322513-B J2
PHE PHE
AFO PHO
R1
DS901
R912 CL-200YG PHE PHE 180
330 R2 180
PHNI PHNI PHONE
GND
GND
L2
GND
DS904 METER BACKLIGHT HF50ACC322513-B
R914 GND
CL-200YG MAX 11.9V
330
MIN 5.1V GND
GND
METER BACK LIGHT
PHONE BOARD
PWRK
FRONT
J921 J1
W1 J2
DASH DASH
DOT DOT
ELEC-KEY
GND
+ GND
- GND
GND
+ -
GND
GND
GND
GND
KEY BOARD
J451
SPE
CP401
to
MAIN-A unit
D701 J352
DAN222 SSP
CP402 CHASSIS
J452 P1
SSP SSP
CP411 + SP
MEASUREMENT CONDITIONS SSPE SSPE
-
VOLTMETER :50kΩ/VDC CP412
OSCILLOSCOPE :20MHz 1MΩ 25pF
SUPPLY VOLTAGE:13.8V
DISPLAY : 14.1MHz USB
DISPLAY BOARD
R502
15k
-7R5V
R501
+4R5V
1k
HD
POLC
+14V
R1526
C1521 0.1 100
C1409 C1201 C1211 C1221
0.1 0.1 0.1 0.1
IC1521a
8 M5218AFP
C1408 3
0.1 + 1
2 BL
-
GL
4
C1407 RL
0.1
C1522 R1527 D1201 D1211 D1221
0.1 100 MA8030 MA8030 MA8030
C1403
0.1
Q1201 Q1211 Q1221 IC542
2SA1576 2SA1576 2SA1576 TK16105M
1 8
32 2 7
C1110
31 3 6
0.1
30 4 5
29
28
27 R1551
26 GAM2 100
25 GAM1
Q1551
24 CONT1
2SC4081
23 BRGT
22
21
20
Q1553 IC490
C1554 S-80942ANMP-DD6
19 2SA1576
10
18 1 5 5
OUT CO 1
17 2
VDD 2
C1553
10 3 4
VSS NC
COMO R1552 3
100
Q1554
2SC4081
Q1552 IC492
2SA1576 TC4S81F
-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
GND unit J891
-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
MIC BOARD
C1
0.0047
J1
7 1
Q321 OFF 4.8V 6 8 2
DTC114EE UP 0.6V
5 3
DOWN 1.2V
4
FRONT
J322 W2 J2
MICI MICI L1 100µH
M8V M8V
MUD MUD MUD
L3 100µH
SQLS SQLS L4 100µH
MSND MSND
GND GND
MMICE MMICE
AFO AFO
L6
HF50ACC322513-B
Q512
J531
2SB1132 Q514
2SB1132
L5V
HD
VD VD
POLC POLC
IC511d
Q511 NJM2902V Q515 GND
D512 C513 W504
DTC114EE 12 DTC114EE
RD5.1M 0.1 + 14
13 L5V
-
RL
GL to
Q513 LCD
BL
DTC114EE unit
VCOM
4 GND
W512
IC511c W502
12.1V
IC511b NJM2902V L/R
4 12.1V
2 NJM2092V 10 U/D
+ 1 + 8
3 5 9
R511 - + 7 - W506
10k IC511a 6
11 -
NJM2092V N/P
L18V
-15V
CP5