Vizio E371VA Power Problem?

[Mark355]

First post from a newbie! My Dad of 84 was the proud owner of a Vizio E371VA which, of course fails after the warranty has expired......he doesn't have any paperwork anyway. Anyhow, the "Vizio" front logo will light, and when you "power" it up the logo dims slightly and the screen and logo will flicker slightly. That's it. After researching on the web I found countless references to the bad cap easy fix, so I'm thinking even I can handle that. After taking the back panel off, I find none of the caps to look bad, i.e. popped or leaking. Any thoughts? My Dad was ready to toss it and get another one.....which he really can't afford. SO I thought I would at least look at it. Oh yes, I do own a multimeter, but have limited knowledge on how to use it. I'm willing to learn, and hey, the unit is worthless now anyway. lol I can take and post pics if needed.

Thanks in advance,

Mark

[retiredcaps]

Re: Vizio E371VA Power Problem?

I can take and post pics if needed.

Post clear focused top down view pictures following the instructions in my sig file below exactly.

We want the composition to look like the following

https://www.badcaps.net/forum/showpo...94&postcount=1

[Mr Bill]

Re: Vizio E371VA Power Problem?

definitely post pictures of the power supply and the whole rear of the tv. You say the vizio logo dims. Is this the logo on the cabinet of the front of the tv or the splash screen before the tv turns on? Does the tv turn on despite the flickering?

[Mark355]

Re: Vizio E371VA Power Problem?

Thanks for the quick responses. I'll take pics tomorrow. Oh yes, the logo is on the bottom of the unit, not the splash screen. When I push the power button, the logo dims slightly and the screen lightly flickers as well, that's all.

Mark

[cashkennedy]

Re: Vizio E371VA Power Problem?

Are you able to turn the tv "off" with the button? (as in will the logo return to amber after pressing the power button again)?

Most likely this is bad regulators on the main board. You should search for the service manual (available at elektro tanya most likely). Then follow the DC-DC regulator testing path. You will need a multimeter for this.

[Mark355]

Re: Vizio E371VA Power Problem?

Yes, I can turn the unit "off" with the power button i.e. the logo will dim slightly to the standby mode. Press it again and the logo will brighten and the screen as well as the logo will start to flicker slightly. Hope to get photos up ASAP. Busy day today though.

Thanks,

Mark

[cashkennedy]

Re: Vizio E371VA Power Problem?

Is your logo changing color at all? Or just dimming?
(Does it go from amber to white )

[Mark355]

Re: Vizio E371VA Power Problem?

It changes brightness not color. I just fired it back up with the back cover off. When I plug the power in via the chord the "VIZIO" logo lights. Then when I push the power button on the side the logo actually brightens, and sometimes the screen will flicker and I noticed that a blue LED on one of the boards flashes as well. Also any opening in the metal backing I can see the same flickering, but it is much brighter. I can also hear a faint clicking sound. I have tried to upload the pictures that I took, but for some reason the upload times out. I have re-sized them below the 2000 x 2000 and they are under 2megs. Oh well.

Thanks for your replies,

Mark

[tom66]

Re: Vizio E371VA Power Problem?

1280x1024 is fine for us, just take some macro shots of important areas.

[Mark355]

Re: Vizio E371VA Power Problem?

Weird, I had to upload the pics in Explorer, wouldn't in Mozilla. Go figure! Hope these help.

Thanks,

Mark

[tom66]

Re: Vizio E371VA Power Problem?

Darn - that's the first Vizio I've actually seen using cheap capacitors. For a "cheap" brand, Vizio are generally quite high quality, but I guess even they will shave a penny here and there.

Anyway, use your multimeter on the 200V DC range to check the outputs of the supply. (Don't worry, we aren't measuring 200V, we're measuring 24V.) Check the red wires going to the board of the left (looking from the back.) Place the black probe in part of the case (screw hole, etc), the red probe on the pins of the wires on either side. You should see around 24V give or take 1V.

Do -NOT- touch any of the heatsinks of the power supply, as they will sting you with some live voltage. The rest is safe to touch, with the exception of the high voltage for the backlights, but that is well covered up.

[budm]

Re: Vizio E371VA Power Problem?

Since this power supply has PFC Voltage booster circuits, please also check the DC voltage on that large 450Vdc cap when TV is off, it should be around 165~170Vdc, then turn on the TV, the voltage should go up to 380~400Vdc, it does, that means the PS_ON is OK, if not, it can be due to no PS_ON or failed PFC circuits.

[Mark355]

Re: Vizio E371VA Power Problem?

Anyway, use your multimeter on the 200V DC range to check the outputs of the supply. (Don't worry, we aren't measuring 200V, we're measuring 24V.) Check the red wires going to the board of the left (looking from the back.) Place the black probe in part of the case (screw hole, etc), the red probe on the pins of the wires on either side. You should see around 24V give or take 1V.

Well I checked the red leads and they all check at 24.8 volts. @budm, are you talking about the large black cap on the power supply board, at position C909? If so, any suggested precautions on the multimeter settings or how I should test?

Thanks,

Mark

[selldoor]

Re: Vizio E371VA Power Problem?

Hi- Yes that is the capacitor he means.
These are high voltages so great care needed
Set your meter to 600vDC and put the black (negative) probe on the
Negative leg of the the capacitor. Put the red (positive) probe on the
positive leg of the capacitor. Do not hold the probes too near to the
metal points.
Remember heat sinks will carry a voltage that will give you a nasty jolt

[Mark355]

Re: Vizio E371VA Power Problem?

OK, with the TV plugged in and in stand by mode the large cap read 173 volts, with the set on it read 411. And hey, I didn't cause a single arc!

Thanks again,

Mark

[budm]

Re: Vizio E371VA Power Problem?

OK, that means the PS_ON signal is good, then next thing we will need to find out if you do have 24vdc for the inverter board. On your first picture, on the top left there is a connector (24vdc, red and black wires) that goes to the Inverter board on the bottom left of the picture, disconnect that cable, turn the TV on and see if you have 24vdc at the top left connector.

[tom66]

Re: Vizio E371VA Power Problem?

OK, that means the PS_ON signal is good, then next thing we will need to find out if you do have 24vdc for the inverter board. On your first picture, on the top left there is a connector (24vdc, red and black wires) that goes to the Inverter board on the bottom left of the picture, disconnect that cable, turn the TV on and see if you have 24vdc at the top left connector.

The OP already checked that, but there are some other voltages to check.

OP, Can you post some close ups of the connector going from PSU to main board?

I note that there is an orange cap without a safety vent, this could easily be failed without knowing, but you would only find out for sure when it went "bang"! That seems a little dangerous to me....

[budm]

Re: Vizio E371VA Power Problem?

Oops, I missed that info, sorry.

[Mark355]

Re: Vizio E371VA Power Problem?

Thanks for the continued suggestions. I hope the attached pics are what you needed. Also, in the second pic, is this the orange cap that you were talking about?

Thanks again,

Mark

[tom66]

Re: Vizio E371VA Power Problem?

I don't see a second pic but thanks for the connector. With main board plugged in check the voltage on the +12V and +5V like you did for the inverter power.