Hello, I'm hoping for some help debugging what broke on my Vizio P702ui-P3. I had originally thought it was an issue with the power supply board, but based on these 2 threads am starting to think main board instead:
https://www.badcaps.net/forum/showthread.php?t=51443
https://www.badcaps.net/forum/showthread.php?t=80351
My case is different than either of these. Here's a summary of what I've found so far:
- ~160V on main caps as expected with power off.
- Set's power LED lights when powered on, then I see the following
- SPDIF lights up
- ~380V on main caps
- 3.8V on AC-DET
- 5V on PS-ON
- ~24V on all 24V1 on CN301
- ~12V on +12VS and 12V-AU on CN201
- 0V on "12V T CON" on CN201
- 0V on "T CON_ON" on CN201
- 0V on "12V T CON" on CN202
if I use a 1k resistor to try to pull up "T CON_ON" it has no effect, it is still held low by main board.
If I disconnect CN201 to main board, then use a 1k resistor to try to pull up "T CON_ON" then get correct ~12V on "12V T CON" pins.
This makes me think that the main board is keeping the PS board from powering the "12V T CON". Main board is not dead though, as the SPDIF lights and I can use the power button to power the set on and off. Also, the heat sink warms when powered on.
Any advice is appreciated. Would like to rule out other things before ordering a new main board.
Thanks,
Russ
https://www.badcaps.net/forum/showthread.php?t=51443
https://www.badcaps.net/forum/showthread.php?t=80351
My case is different than either of these. Here's a summary of what I've found so far:
- ~160V on main caps as expected with power off.
- Set's power LED lights when powered on, then I see the following
- SPDIF lights up
- ~380V on main caps
- 3.8V on AC-DET
- 5V on PS-ON
- ~24V on all 24V1 on CN301
- ~12V on +12VS and 12V-AU on CN201
- 0V on "12V T CON" on CN201
- 0V on "T CON_ON" on CN201
- 0V on "12V T CON" on CN202
if I use a 1k resistor to try to pull up "T CON_ON" it has no effect, it is still held low by main board.
If I disconnect CN201 to main board, then use a 1k resistor to try to pull up "T CON_ON" then get correct ~12V on "12V T CON" pins.
This makes me think that the main board is keeping the PS board from powering the "12V T CON". Main board is not dead though, as the SPDIF lights and I can use the power button to power the set on and off. Also, the heat sink warms when powered on.
Any advice is appreciated. Would like to rule out other things before ordering a new main board.
Thanks,
Russ
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