Vizio E470i no power

[AcGeorgiegirl]

Re: Vizio E470i no power

Uh-oh! I was using the pins of the connector, already, but with the LED connected to the board. I couldn't find an easy way to turn the board over with it still connected to the power, the Main, and the LEDs.

[budm]

Re: Vizio E470i no power

When the LED driver output does not see the load, its Voltage will rise up to try to force current through the load due to the fact that it is constant current source, the current is held constant but the Voltage is varies to maintain constant current.
You can disconnect the LED connector and check the DCV at the pins of the connector that go to the Anode of the LED strings, you will probably see more than 100V also.

[AcGeorgiegirl]

Re: Vizio E470i no power

Ok. Should I attempt getting voltage of the 2 filter caps? I've bought a new desoldering iron, and won't be near as a pain to unconnect a lead on each for testing, I hope!

[budm]

Re: Vizio E470i no power

If if the reading is 99V per ECKING, then you do have open circuit (no load) Voltage due to open LED connections/open LEDs.

[AcGeorgiegirl]

Re: Vizio E470i no power

The LED connector should read around 99VDC

I get 126 average voltage on the LED pins, instead. I guess this may be ok, considering the % of accuracy into account. But if I'm getting this, why the heck won't the backlight come on? The blu-on is at 3.2, unless jumpered to the standby- and then it's 5.26. The guys on here helping me were deciding if it's a bad LED string, so I'll wait for what they think after reading my latest test results.

[AcGeorgiegirl]

Re: Vizio E470i no power

What does it mean when you get a voltage test that runs up and down like that? I haven't found any info for this, yet.

[AcGeorgiegirl]

Re: Vizio E470i no power

Ok. It doesn't cycle from high to low v, but keeps circling. My DMM is set for 200 and each pin ranges from 131 down to 120 or so, and then cycles back up and back down repeatedly.

I tested again, and found that, in addition to my previous posting(above)....I held the prong to the pin after turning tv off, watching how it behaved as it depleted, I found that they will go down to around 26, but then rise up to 60.8 and they hold there. That's the only time a reading actually holds still. Unplugging the tv, of course, then they deplete to 0.

[AcGeorgiegirl]

Re: Vizio E470i no power

Hi Ecking767,
Thanks for the offer. I might take you up on that. I got 2 of these Vizio E-series smart tv's...one is this one and the other is it's warranty replacement, which has never been used 1 minute because the panel got cracked coming out of the box! So...I'm trying hard to get this one working again, at least. The other one is a bit larger, a 48". Any info you (or one of the other guys) may have as far as whether these panels can be swapped for others similar, or do they have to be the exact make/model?

[ecking767]

Re: Vizio E470i no power

Hello AcGeorgiegirl,

I have a working Vizio E470i-A0 with a crack screen on my work bench, I'm about to dis-assemble this TV for parts,so if you need any voltage measurements I can confirm these reading.

The LED connector should read around 99VDC


if you need the LED strips please let me know.

[AcGeorgiegirl]

Re: Vizio E470i no power

Ok. It doesn't cycle from high to low v, but keeps circling. My DMM is set for 200 and each pin ranges from 131 down to 120 or so, and then cycles back up and back down repeatedly.

[newtothis]

Re: Vizio E470i no power

Plug all boards in when doing the test

[AcGeorgiegirl]

Re: Vizio E470i no power

Thanks, guys- You were telling me this, but I didn't get it! Quick question...should the psboard be connected to the other boards for this test, or just to the ac?

[newtothis]

Re: Vizio E470i no power

***EDIT***

budm got there while my image was uploading

[budm]

Re: Vizio E470i no power

Please see the attached picture.
BTW, you can take the measurement on the top side of the board right at the connector pins.

[AcGeorgiegirl]

Re: Vizio E470i no power

I hope you know what the Diode symbol is

I attached a pic with marks I made to show you where I am looking. Yes, the anode side is the part that looks like an arrow. I just don't know where each string's anode is, on the board. I see where you drew the diode symbol for each string, and the only other symbols I see are the ones I circled in blue, which are two that look the same...do I touch the probe to the anodes of each of these? I also circled the area that originally I was focused on, the "Need Verification". I was thinking this was one of the string's area you wanted me to test, but didn't know how to locate the anode portion(!). I am looking for a soldered post that's an anode side of a "string", though not understanding, I think, what a string looks like. Maybe I'm thinking wrongly...that it is similar to a cap's connectors or a resistor's. Sorry I'm so confused!

[budm]

Re: Vizio E470i no power

Ok, I see where you marked for measuring a LED string, but I'm not sure there's supposed to be two of these...one for each string?

I hope you know what the Diode symbol is to be able to tell what is Anode and what is Cathode, please look it up. You will put the meter in DCV, BLACK probe on the chassis, the RED probe on the Anode of the the LED string #1, turn on the TV and observe the readings, then turn off the TV, then do the same on the ANODE of the LED string #2. You see that I drew Diode symbol on the connector that goes to the LED strings of the panel.

[AcGeorgiegirl]

Re: Vizio E470i no power

...also, with testing the filter caps, I'm not certain my DMM will give nearly accurate reading unless I desolder/disconnect one lead. Is that true? Mine doesn't read capacitance or ESR...just ac/dc volts, diodes, amps, and ohms.

[AcGeorgiegirl]

Re: Vizio E470i no power

I don't "get" strings, I think, is what's tripping me up. Are the 2 circles at the ends of the line you're pointing to the anodes for string 1 and 2?

[AcGeorgiegirl]

Re: Vizio E470i no power

You need to monitor the Anode of the LED string 1 and string 2 to see what DCV you get when you first turn on the TV

Ok, I see where you marked for measuring a LED string, but I'm not sure there's supposed to be two of these...one for each string?

[AcGeorgiegirl]

Re: Vizio E470i no power

Off topic but are you female? Just your username indicates it

Yes.