Icom IC-91A Service Manual page 41

SECTION 10 BOARD LAYOUTS
10-1 LOGIC UNIT
• TOP VIEW
V90
V85
V80
V75
V70
V65
V60
V55
V50
V45
V40
V35
V30
V25
V20
V15
V10
V5
V0
H0 H5 H10 H15 H20 H25
10-2 MAIN UNIT
• TOP VIEW
J702
39 EXTMIC
DAFOUT
DASTB1
1
10-3 RF UNIT
• TOP VIEW
1
J1001
H30 H35 H40 H45 H50
30
to MAIN unit J703
10 - 1
EXT MIC
GND 40
AFO
INTSP
AAF
CLONE
ANOIS
DIUD
BNOIS
DICK
BRSSI
PTT
VOL
BAF
S-LV
+3V
INTPTT
ATONE
BTONE
CHG
IOSTB3
TTEMP
IOSTB2
UNLK
BPS
BPLSTB
IOSTB1
REFMOD
TXC
APLLSTB
HV
PLLDATA
SQL
+5.5V
GND
MOD
DATA
VCC 2
CK
SQL
to LOGIC unit J401
H0 H5 H10 H15 H20 H25
CHASSIS
J1
V50
CHASSIS
MP28
V45
CHASSIS
W1
V40
V35
V30
2 16
V25
J800
V20
1 15
to VCO unit J1 V15
15
V10
V5
16
V0
H0 H5 H10 H15 H20
EXT SP
V50
V45
10-4 UT-121 ( Optional Product ;
V40
• TOP VIEW
V20
V35
V15
V30
V10
V25
V20
V5
V15
V0
H0
V10
V5
V0
H30 H35 H40 H45 H50
DC IN
BATT+
BATT- from battery
H25 H30 H35 H40 H45 H50
CODEC UNIT for IC-91AD)
H5 H10 H15 H20 H25 H30 H35
10-5 VCO UNIT
• TOP VIEW
V20
V15
V10
V5
V0
H0 H5 H10 H15 H20