Vizio E470i no power

[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.

[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

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?

[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

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

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.

[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

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

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

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 you remove the Female LED connector from the board you will see the male pins on the board to make the measurement.

[AcGeorgiegirl]

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.

Thanks Budm,
I'm wondering if my DMM's reading of 120-131 is accurate enough to determine....could it be enough of a margin of error in it's reading that 99v is still correct..or is the difference too much? How is this fixed? Do I now need to find which LED's are faulty, or is it a matter of replacing the whole thing?

[AcGeorgiegirl]

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.

Could you tell me if I'm getting the right v's with other areas of the power supply, so if I fix the LED issue, all will be ok...or is it too late!?
Particularly...the connector to Main, should it be 3.2v for pins 2 through 5 when the tv is on? I think the other guys determined these were ok, but I just want to make sure before I start replacing parts.

[ecking767]

Re: Vizio E470i no power

I didn't see any issue with the main power connector voltage measurements.
I will focus on the LED strips inside the LCD screen itself.

Please confirm the voltages on the LED connector with the TV power on. You can make contact from the back side of the connector using your Multimeter.

That will give you your answer

[AcGeorgiegirl]

Re: Vizio E470i no power

Yes, that's actually the spot where I have been testing already. Same as before, I keep getting a range from 120 up to 131 or so, and my DMM cycles up and down this scale repeatedly.

[ecking767]

Re: Vizio E470i no power

Yes, that's actually the spot where I have been testing already. Same as before, I keep getting a range from 120 up to 131 or so, and my DMM cycles up and down this scale repeatedly.

If 120vdc is being applied to the LED's strips and they don't light up, then one or more LEDs are open and no current is flowing. You will have to disassemble your LCD panel to inspect the panel LEDs.

To disassemble the LCD panel is a delicate process and good assembly and dis assembly skills are need.

[AcGeorgiegirl]

Re: Vizio E470i no power

Gotcha. I am willing to try doing this, and will research the fine details to see if I should. Getting it dis-assembled is one issue, but knowing what to look for/inspect the LEDs, I assume I'd need to know ahead of time? So, how are these replaced? Will I find that I can or can't replace only the string that's faulty?...or will I most likely end up needing to buy the entire set along with the board?

[budm]

Re: Vizio E470i no power

if you can get the LED assemblies from ECKING then you can just plug them into the connector of the LED driver to see if it will light up before taking your panel apart.
Hope fully he will take good pictures to show how the panel comes apart.

[AcGeorgiegirl]

Re: Vizio E470i no power

Sounds great, thanks, budm! (And thanks to you, too, ECKING!). Now, how much is this gonna' cost me???

[ecking767]

Re: Vizio E470i no power

I will send you the link for the LED strips by private message