CONFIDENTIAL
–
DO NOT COPY
Page 9-5
File No. SG-0268
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TROUBLE
OF
DC-DC
CONVERTER
Start
J1
The voltage is about +5V (+5VSB)
1. Check power board
2. Check power cable, F6 & connection J1
3. Check U4 pin3 (+5VSB) & pin2 (+3V3SB)
J1 PIN 2, 3, 4
The voltage is about + 12V while power switch on
1. Is J1 connection good
2. Check J1Pin1 is up to about 5V?
3. Check power board
4. Check F2
U1 pin 5 6 7 8
The voltage is about +5V while power switch on
1. Check F6 & U1
2. Check OPWRSB (R274)
3. Check U1 pin1 & 3
U2, U4 pin2
The voltage is about +3.3V
1. Check F6 & U1
2. Check U2, U4
U8 pin2
The voltage is about AV1.2V while power switch on
1. Check F1 & U1
2. Check IC3 pin3,4
U5 pin2
The voltage is about DDRV (+2.5V) while power
switch on
1. Check J1 Connect
2. Check U5 pin2
U11 pin3
The voltage is about +12V to +5V_Tuner while
power switch on
1. Check F2
2. Check U11 pin1 (+12V) & pin3 (+5V_TUNER)
END