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TROUBLE OF DC-DC CONVERTER
J1 PIN9,PIN10,PIN11
J1 PIN 2,3,4
U1 pin 5 6 7 8
U11 pin1 & pin2
CONFIDENTIAL
DO NOT COPY
–
Start
Yes
Yes
Yes
U7 pin2
Yes
U8 pin2
Yes
U9 pin2
Yes
END
The voltage is about + 5V(+5VSB)
N0
1. Check power board
2. Check power cable, F1 & connection J1
3. Check U4 pin1 (+5VSB) & pin2 (+3V3SB)
The voltage is about + 12V while power switch on
1. Is J1 connection good
N0
2. Check J1 Pin1 is up to about 3.3V (+3V3SB)?
3. Check power board
4. Check F2.
The voltage is about +5V while power switch on
1. Check F1 & U1
N0
2. Check OPWRSB (R11)
3. Check U1 pin1&2 or pin 3&4, should have -1V
more.
N0
The voltage is about +3.3V
1. Check F1 & U1
2. Check U27 pin2
The voltage is about +1.2V while power switch on
N0
1. Check F1 & U1
2. Check U8 pin2
The voltage is about +2.5V while power switch on
N0
1.Check J1 Connect
2.Check U9 pin2
The voltage is about +12V to +5V (for Tuner) while
N0
power switch on
1. Check F2
2. Check U11 pin1 (+12V_AP) & U11 pin2
(+5V TUNER)
Page 9-5
File No. SG-0271
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