Vizio SV472XVT Service Manual page 28

TROUBLE OF DC-DC CONVERTER
J1 PIN10,11,12,13,14
CONFIDENTIAL – DO NOT COPY
Start
Yes
J1 PIN 1,2
Yes
U1 pin 5 6 7 8
Yes
U5,U7,U88,U89
Yes
U50
Yes
U73,U94,U71
Yes
J6 pin1,2
End
The voltage is about + 5V(+5VSB)
1. Check power board
No
2. Check power cable, F10 & connection J1
3. Check Standby power
(+5VSB/+3V3SB/2V5VSB/1V8VSB/1V2VSB)
The voltage is about + 12V while power switch on
1. Is J1 connection good
2. Check J1 Pin17 is up to about 3.3V ?
No
3. Check power board
4. Check F4
The voltage is about +5V while power switch on
No
1. Check F1 & U1
2. Check POWER_ON_5V (R7)
3. Check U1 pin5,6,7,8
The voltage is about +3.3V
No
1. Check F10 & U1
2. Check U5,U7,U88,U89 Power
No
The voltage is about +1.2V while power switch on
1. CheckU50 pin1,2,3,4
2. Check U50 pin 5,6,7,8
No
The voltage is about +2.5V while power switch on
1.Check J1 Connect
2.Check U73,U94,U71 Power
No
The voltage is about 18V while power on
1. Check J6 pin1,2 (AUD_PWR)
Page 9-5
File No. SG-0325