Acer AL1917 Service Manual page 45

+5V
C701
NC
+12V
C706 C707
GND
+
GND
0.1uF
100uF/25V +12V
GND
+5V
+5V
3,4 +5V
GND
C710
C709
+
0.1uF 100uF/25V
R706 NC
4
Adj_BACKLIGHT
R707
4.7K
+3V3
R716 R717
10K
10K 1/16W
NC
R725
4 on_Panel
4.7K 1/16W
C718
0.1uF
SOT-223
U701
+3V3
NC/LT1117-18
3 2
VI VO
4
VO
C703 + C704
100uF/25V NC
BL_ADJ(DC) R31 C51 R32 R29 R33 Q4
0V ~ 3.3V 4.7K 1UF 0 X X X
0V ~ 5V 4.7K 1UF X 1K 4.7K MMBT3904
BL_ADJ R31 C32
P W M 47 N.C
D C 4K7 1uF
+5V
R708
+12V 4
CN701
10K 1/16W
1 2 BL_ON R710
3 4 BL_ADJ
5 6 +12V
7 8 GND C711
9 10 +5V R712
GND
11 12 0.1uF
Q703
PMBS3904
CONN
VCC5V
R701
1K 1/16W
R705 4.7K
1/16W
Q701 C708
PMBS3904 1uF
1/16W
+3V3
+5V
VLCD
VLCD 5
+5V +3V3
R714 R715
1/16W NC
R721 R722
Q704
R723 51K 1/16W AO3401L 0 1/16W NC
Q706
C715
PMBS3904
0.1uF + C717 R727
10uF/16V 10K 1/16W
H1 H2
+3V3
9 5 9 5
9 5 9 5
4 4
4 4
TP TP
+5V
NC R711
10K 1/16W
4.7K 1/16W
on_BACKLIGHT 4
D704(SSM12L) Vf=0.38V and If=1A.
So when system power on, the
system loading is about 400mA
(3.3V is about 200mA and 1.8V is
about 200mA), So D35 changed
from 1N4148(or BAT42) to
SSM12L(schottky diode).
P.S: The 1N4148 Vf=0.7V~1V can't meet
LDO spec. The BAT42, Vf is OK but the
If=200mA(forward current) can not
meet current spec.
For RSDS and Panel VCC=12V
+5V
+5V +12V
R718 R729 R719
NC/10K NC/10K NC/10K
R724 51K
R726 NC/4K7 C716
Q707
4 on_Panel_12V
0.1uF
PMBS3904
C720
NC/0.1uF
44
H3
9 5
9 5
4
4
TP
B
D702
1N4148
C705
1uF/16V R704
100 1/16W
+5V PC5V Recommond to used "Blue" parts circuit
for VCC1.8V if you want to suppoert DDC
3,4 +5V PC5V 3
function when system power off
R732 R709
+5V 10 1/16W 0 1/16W
3,4 +5V
D704
D703 TO-263
SMAL140 BAT54C
U702
3
VIN VOUT
VOUT
1
ADJ
C713 AIC1084-33PM
0.1uF
VLCD_12V
+5V +12V
VLCD_12V 5
R730
R731
Q705 0 1/16W NC
AO3401L
+ C719 R728
Title
NC/10uF/16V NC/4K7
Size
B
Date:
VCTRL 4
R702
51 1/16W
VCC1.8
+ C702
VCC1.8 4
4.7uF/16V
D701
1N4148
R703
Q702
2K 1/16W
CHT2907
VCC3.3
VCC3.3 4
VCC3.3
2
VCC3.3 4
4
R713 C712
C714
+
NC
100uF/25V 0.1uF
R720 0 1/16W
12/21 MODIFY
TSUM16AK
Document Number Rev
POWER A
Monday, May 30, 2005 Sheet 1 of 5