Help with Vizio E320VA power board

[Mark67]

Hello, I'm hoping for some help. I have a Vizio (E320VA) that lost it's picture right after a nearby lighting strike. No other components were effective. So I scanned the internet for some education. And this forum had the best detailed explanations, by far.
So here's where I'm at: I visually inspected all three boards and everything appears fine on all three. So then I dove into the power board,( the first in the line of the components that would've taken the spike?) and took voltage readings at the 13-pin connector. Here's what I found (in the tested value column:
label tested value
black on/off 1.1
brown PDIM 2.07
Red 12+ 12.02
orange 12+ 12.02
yellow gnd 0.01
green gnd 0.01
blue gnd 0.01
purple 24+ 25.24
gray 24+ 25.24
white PS-ON 5.02
black 5+ 5.2
brown 5+ 5.2
red ACO 0.01
So to my un-educated mind, the board would seem to be doing it's job? Its the pins without a posted value that I'm uncertain about.
And of course, IF the board is good, what's my next step?
I am comfortable poking around this stuff, and am anxious to see if I can find a solution that doesn't involve buying a whole new set.
Any input on the reading I posted here would be greatly appreciated.
Mark

[Ltank]

Re: Help with Vizio E320VA power board

I tried to look up service manual but no luck, wanted it confirm the Black on/off, PDIM,
PS-On and ACO voltages. If they are correct then the Power supply voltages look good. Did the backlights turn on? If the backlights turn on then the inverter and bulbs are good. Do you have sound? Lots of times I see damage to the main board at the HDMI ports when lightning damages set. Try another HDMI port.

[Mark67]

Re: Help with Vizio E320VA power board

Hi Ltank,

Thanks for the effort of looking for the service manuals. Those are my question items too.

As for your next question, there is nothing when I turn the set on. The vizio logo in the front lights up, there is a blue light I can see from the back side, that comes from what I think is the inverter. That's it. No menu on screen, no sound, not even hissing. Perhaps I'll mess around some more with it this evening. The natives are getting restless.

[Ltank]

Re: Help with Vizio E320VA power board

Alot of times strikes take out the ports that are connected at the time. HDMI ports in particular. Measure the voltages at the voltage regulators on the main board. Find out what one might be missing or shorted to ground. I would look at the 3.3 volts on the main board. Alot of HDMI chips use this voltage. Main boards have limitations that the average tech can repair due to sometimes to parts availability. Some can be very tedious to remove and replace.

[Mark67]

Re: Help with Vizio E320VA power board

Thanks, I'll go check that right now.

[starmatter]

Re: Help with Vizio E320VA power board

I too am experiencing power problems with mi VIZIO E320VA. My wife tells me that she heard a pop sound followed by a complete power down. I have measured the AC voltage across the main fuse and it reads approx. 110VAC. I then proceeded to measure the DC voltage as suggested above. I get absolutely nothing on all pins. There may have been a lighting strike but we really can't recall. The symptoms are no picture, no sound and no lights.
Thanks,
pw

[dskall]

Re: Help with Vizio E320VA power board

Need good clear straight on pictures of back of tv with cover off and each board.

[starmatter]

Re: Help with Vizio E320VA power board

Here are some pictures(attached).
Thanks,
pw

[budm]

Re: Help with Vizio E320VA power board

What is the status of the 'VIZIO' indicator lights? Amber when TV is OFF and White when power switch is activated?

[starmatter]

Re: Help with Vizio E320VA power board

VIZIO indicator light is dark and never turns on at all like it did before.

[dick_barton]

Re: Help with Vizio E320VA power board

Have you checked the fuse F901 for continuity.
What voltage do you have with the meter probes connected to each pin of the large capacitor C926.

[starmatter]

Re: Help with Vizio E320VA power board

The fuse F901 shows good. I don't see a C926 but I do see a rather big one C920. I got different readings between different meters for some reason. I have two cheep ones and a more expensive one. ALL three of them read the same between the fuse F901 & ground which is roughly 110-120VAC. But between the + side of C920 & ground my two cheep meters agree at roughly 120VAC but my more expensive one reads around 74VAC.
Thanks for your help!
pw

[dskall]

Re: Help with Vizio E320VA power board

You read the large capacitor across the terminals in dcv

[budm]

Re: Help with Vizio E320VA power board

The fuse F901 shows good. I don't see a C926 but I do see a rather big one C920. I got different readings between different meters for some reason. I have two cheep ones and a more expensive one. ALL three of them read the same between the fuse F901 & ground which is roughly 110-120VAC. But between the + side of C920 & ground my two cheep meters agree at roughly 120VAC but my more expensive one reads around 74VAC.
Thanks for your help!
pw

You are making Voltage measurement in the Primary hot side of the circuit so do not use chassis GND as the GND ref. for the meter, you need to use the negative leg of the main filter cap as the GND ref for the circuits in the primary side. The fuse is good otherwise you will not get any DCV on the output connectors in the cold side of the circuit.
Main filter cap C920 should have 380~400VDC between the two legs of the cap.
Fusible resistor R801 is good, showing <1 Ohms or so?
Right now I would say you do have main board problem because you are not getting VIZIO logo on the bezel to even come on.

[starmatter]

Re: Help with Vizio E320VA power board

Thanks for clarifying that ground reference point. Those measurements left me scratching my head. Now that I'm measuring VDC between the pins of C920 all three of my meters agree with the result being approx. 160-168VDC.
R801 is good showing <1 Ohms.

When you say main board which board are you talking about?
Paul

[budm]

Re: Help with Vizio E320VA power board

The big green board with the input/output connectors.
Right now the DCV on the main cap should be close to 400VDC if the PFC Voltage booster is working, so you have more than one bad boards.
BTW, Does PS-on Voltage change state at all when the power switch is toggle on-off?

[starmatter]

Re: Help with Vizio E320VA power board

I saw no voltage change on the large cap during power on/off. What's weird is when I probe the large cap for voltage I see higher numbers 400 to 500VDC but then it immediately drops to around 160VDC.
What or where is the PFC Voltage Booster?

[tvtanner]

Re: Help with Vizio E320VA power board

I too am experiencing power problems with mi VIZIO E320VA. My wife tells me that she heard a pop sound followed by a complete power down. I have measured the AC voltage across the main fuse and it reads approx. 110VAC. I then proceeded to measure the DC voltage as suggested above. I get absolutely nothing on all pins. There may have been a lighting strike but we really can't recall. The symptoms are no picture, no sound and no lights.
Thanks,
pw

Hi- the only way you can measure voltage across fuse is because its bad. its open. burned out. Before you replace fuse check for short. usually its a rectifier.

[starmatter]

Re: Help with Vizio E320VA power board

Oh thanks for clarifying this for me. I meant to say that I probed both ends of the fuse with ground. I just measured continuity across the fuse and got 0 Ohms.

[starmatter]

Re: Help with Vizio E320VA power board

So does anyone believe this TV is worth repairing? Is it worth replacing all boards?
Thanks,
Paul