No power on Vizio D32F-E1 TV

[frannyjunk]

The TV is dead. No lights whatsoever. I measured voltage on the power supply board (PLTVGL451XAQ6) CN9101 connector with power plugged in (but not connected to mainboard). Voltages are as follows:

Pin 1 = DIM - 0V
Pin 2 = on/off - 0V
Pins 3, 4 = NC - 0V
Pins 5, 6, 7, 8 = GND - 0V
Pins 9, 10 = +12V audio - 12V
Pins 11, 12, 13, 14 = +12V - 12V
Pins 15, 16 - 0V

No sure which pin is standby, but no pins measuring 3V/5V. Is the power supply board bad?

[neilc6]

Looks like no separate PS-ON signal and power supply is always on at 12V. ON/OFF is backlight on signal. If you have stable voltages and the TV is dead, main board is suspect.

[budm]

Please attach good clear pictures of the whole backside of the TV showing all the boards, and good clear straight shot of the whole power supply board so we can see what we are dealing with.

[nomoresonys]

Retest as in post #1 but with mainboard hooked up, what do you get.

[frannyjunk]

Originally Posted by budm

Please attach good clear pictures of the whole backside of the TV showing all the boards, and good clear straight shot of the whole power supply board so we can see what we are dealing with.

Pictures attached.

[frannyjunk]

Originally Posted by nomoresonys

Retest as in post #1 but with mainboard hooked up, what do you get.

With power and mainboard hooked up:

Pin 1 = DIM - 0.1V
Pin 2 = on/off - 0.07V
Pin 3 = NC - 3.24V
Pin 4 = NC - 0V
Pins 5, 6, 7, 8 = GND - 0V
Pins 9, 10 = +12V audio - 11.8V
Pins 11, 12, 13, 14 = +12V - 11.8V
Pins 15, 16 - 0V

No signs of bulging caps nor any burnt marks on power supply board nor mainboard.

Which board do I replace?

[R_J]

Take a closer look at U705 on the main board, it looks like it is bad or is it just something on the ic?
You can buy all 3 boards (Power, main & t-con) for $35.00

[frannyjunk]

Originally Posted by R_J

Take a closer look at U705 on the main board, it looks like it is bad or is it just something on the ic?
You can buy all 3 boards (Power, main & t-con) for $35.00

There is something on the surface of the chip, but I think U705 is OK. I was hoping to only buy one board, hence the query on this forum. Any best guess as to the problem board?

[R_J]

Shopjimmy has the main board by itself for $19.95 U705 is a 2.5v regulator, check if it has 2.5v on pin 6.

[nomoresonys]

Looks like you made an error or the board is miss-labeled, "Pin 3 = NC - 3.24V" if that pin is NC which means not connected then it should not have 3.24 volts on it.

[frannyjunk]

Originally Posted by nomoresonys

Looks like you made an error or the board is miss-labeled, "Pin 3 = NC - 3.24V" if that pin is NC which means not connected then it should not have 3.24 volts on it.

Hmmm. I just checked pin 3 again and the reading is 3.24V. Does that mean a short somewhere on the power supply board?

[R_J]

That 3.3v is from the main board and is just not used with this main/power supply configuration, on other models it might be. These main boards and power supply boards are used in many different makes and models, That 3.3v is not a problem.

[frannyjunk]

Originally Posted by R_J

Shopjimmy has the main board by itself for $19.95 U705 is a 2.5v regulator, check if it has 2.5v on pin 6.

Thanks for the Shopjimmy tip! I checked pin 6 on U705, and it read 1.79V when plugged in. Does that mean mainboard is ok?

[R_J]

Originally Posted by frannyjunk

Thanks for the Shopjimmy tip! I checked pin 6 on U705, and it read 1.79V when plugged in. Does that mean mainboard is ok?

No it means you have 1.8v out of a 2.5v regulator ic

[frannyjunk]

Originally Posted by R_J

No it means you have 1.8v out of a 2.5v regulator ic

Lol. Does that mean mainboard is suspect? Given all the data we have, what is your best guess as to the problem board? Any other measurements I should make on any of the boards?

Your help is very much appreciated!

[R_J]

Without a schematic, all you can do is check the numbers on the ic's and see if the voltages are correct, with these main boards and the bga ic's it is hard to work on them. Sometimes it's a problem with the firmware being corrupt, it is hard to say where the problem is.

[frannyjunk]

Originally Posted by R_J

Without a schematic, all you can do is check the numbers on the ic's and see if the voltages are correct, with these main boards and the bga ic's it is hard to work on them. Sometimes it's a problem with the firmware being corrupt, it is hard to say where the problem is.

I am a newbie at this so am looking to arrive at some conclusion based on process of elimination. By the looks of it, without schematics, the power supply board CN9101 connector to mainboard looks to be ok since the voltages appear ok. The mainboard is more complex, and more can go wrong (+ the voltage regulator is reading low). Given this is a bit of a crapshoot without schematics (that I wouldn't know how to read even if I had it) the lead suspect may be the mainboard. I'll wait another day or so to see if others might chime in. If I don't get further advise, I'll buy a used mainboard off ebay (only $9.99) and give it a go.

Thanks for the help RJ!! If you or anyone else have further suggestions, I am all ears.

[nomoresonys]

Being a vizio, mainboard is probably the issue, at 10 bux I'd go for it, see what happens.

[nomoresonys]

Have seen many boards miss-labeled and I never assume til I take a close look at the setup.

[frannyjunk]

Originally Posted by nomoresonys

Being a vizio, mainboard is probably the issue, at 10 bux I'd go for it, see what happens.

Agree. I hope the board on ebay works. Says used but functional. No guts no glory, right?!!