Icom IC-7800 Service Manual Addendum page 244

Aug. 2008
DC-DC UNIT
DC-DC UNIT
J4
LG_PWR
GND
-12V
+15V
+15V
to LOGIC
+15V
unit J820
+8V
+5V
+3R3V
GND
J3
GND
VDD1R5
VDD3R3
to LOGIC VDD5
unit J821 PWRS
C15V
GND
J2
GND
VDD5
GND
+3R3V
+3R3V
+3R3V
to MAIN
+5V
unit J450
+8V
+15V
-12V
GND
J5
+15V
+15V
to PA 200W
GND
unit J450
GND
L21
HF50ACC322513
VDD3R3
L44
BLM31PG121SN1
L41
BLM31PG121SN1
+3R3V
MESUREMENT CONDITIONS
voltage at RX
frequency: 14.1 MHz
mode: J3E(USB)
ANT(RX): no input
(TX): no modulation
Explanatory notes
Digital tester
range: input impedance
VOLTAGE LINE
LG_PWR
-12V
+15V
+8V
+5V
VDD1R5
PWRS
C15V
VDD5
IC21
LM2673S
3.28V
7.95V
L22
L23
H8V
IC41
LM2673S
3.28V
7.89V
L42
L43
+8V
LG_PWR
-12V
+15V
+8V
+5V
VDD1R5
PWRS
C15V
VDD5
FRONT SW ON: 20.7mV
HF50ACC322513
+5V_
HF50ACC322513
VDD5 VDD5
VDD1R5
H8V H8V
-11.8V
-12V -12V
FRONT SW ON: 1.92V
OFF: 0V
LG_PWR
W1
+8V
GND
LG_PWR
+15V C15V
C15V C15V C15V
GND
RL142
GND
AW3023
GND
GND
15.1V
H8V
H8V
D141
H8V
DAN222
8.0V
FRONT SW ON: 20.7mV
OFF: 15.1V
L141
Q141
DTD113ZK
OFF: 0V
+15V
IC61
LM2673S
4.96V
L61
7.98V
L62
CDRH104R
L63
IC81
LM2673S
4.97V
L81
7.98V
L82
CDRH104R
L83
IC101
LM2673S
1.54V 1.21V
L101
R101
HF50ACC322513 270
7.97V
L103
L102
D10F-A814AY
14.8V
197mV
IC121
LM2594M
D10F-A814AY
D123
1 8 RB081L
2 7
3 6
C122
R122
4 5
47k 0.1
-12V
D122
MBRD835LT4
83
GND 12
LG_PWR 6
GND 11
C15V 5
GND 10
C15V 4
to
GND 9
REG unit
H8V 3
GND 8
H8V 2
NC 7
NC 1
+15V
H8V
H8V
H8V
L122
+15V