Hello All,
Have a Vizio E472VL that when I first received appeared dead. Gained access to the boards and verified fuses on the power board. Both T4A and T5A are good. Continuity good and voltage on both sides
Checked voltages on the cold side output connector to the main board. The readings are with the connector to the main board removed.
Pin 1 Dim - 0V
Pin 2 Status - 0V
Pin 3 On/Off - 0V
Pin 4 Standby - 0V
Pin 5 +12 - 0V
Pin 6 +12 - 0V
Pin 7 +12 - 0V
Pin 8 9 10 & 11 Gnd
Pin 12 +5 - Not Steady 5.1 to 5.2V
Pin 13 +5 - Not Steady 5.1 to 5.2V
Pin 14 +5 - Not Steady 5.1 to 5.2V
I checked the voltage across the Bridge Rectifier. I have 174 between the + and -
Next I checked voltages at the SMPS U101. This is a Q0465RS. The readings were as follows
Pin 1 Drain - 174V
Pin 2 Gnd - 0V
Pin 3 VCC - Fluctuating between 9 and 11V
Pin 4 Feedback - Fluctuating between 0 and .2V
Pin 5 Sync - Fluctuating between 0 ans .4V
Pin 6 Startup - Fluctuating between 87 and 160V
I checked the C105 tied to the VCC pin out of circuit. Its good. Have not removed any smd devices yet just been checking them in circuit. Checked all low ohm resistors and high voltage caps around this SMPS. Tested Opto-couplers.
I verified the two rectifier diodes D201 and D202 and Q201 on the cold side output out of circuit with DMM
I verified the four mosfets Q706 - Q709 out of circuit with DMM.
Not well versed on component level troubleshooting and am seeking a little bit of guidance on what to check next. Thinking this might be something easy I am overlooking.
Thanks,
Have a Vizio E472VL that when I first received appeared dead. Gained access to the boards and verified fuses on the power board. Both T4A and T5A are good. Continuity good and voltage on both sides
Checked voltages on the cold side output connector to the main board. The readings are with the connector to the main board removed.
Pin 1 Dim - 0V
Pin 2 Status - 0V
Pin 3 On/Off - 0V
Pin 4 Standby - 0V
Pin 5 +12 - 0V
Pin 6 +12 - 0V
Pin 7 +12 - 0V
Pin 8 9 10 & 11 Gnd
Pin 12 +5 - Not Steady 5.1 to 5.2V
Pin 13 +5 - Not Steady 5.1 to 5.2V
Pin 14 +5 - Not Steady 5.1 to 5.2V
I checked the voltage across the Bridge Rectifier. I have 174 between the + and -
Next I checked voltages at the SMPS U101. This is a Q0465RS. The readings were as follows
Pin 1 Drain - 174V
Pin 2 Gnd - 0V
Pin 3 VCC - Fluctuating between 9 and 11V
Pin 4 Feedback - Fluctuating between 0 and .2V
Pin 5 Sync - Fluctuating between 0 ans .4V
Pin 6 Startup - Fluctuating between 87 and 160V
I checked the C105 tied to the VCC pin out of circuit. Its good. Have not removed any smd devices yet just been checking them in circuit. Checked all low ohm resistors and high voltage caps around this SMPS. Tested Opto-couplers.
I verified the two rectifier diodes D201 and D202 and Q201 on the cold side output out of circuit with DMM
I verified the four mosfets Q706 - Q709 out of circuit with DMM.
Not well versed on component level troubleshooting and am seeking a little bit of guidance on what to check next. Thinking this might be something easy I am overlooking.
Thanks,
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