Vizio E470VL NO Backlight help

[mattstolte]

ok got this tv and at first backlight would come on then shut off, now I cant get backlight to come on, but tv will power up just no backlight. atfirst I thought it was bad power supply now im not sure
I have my
5v standby
12v
ps on is 2.2
I on/off .75v

[budm]

Re: Vizio E470VL NO Backlight help

'I on/off .75v[ATTACH]' Inverter on/off is too low, <1VDC = OFF, >2.5VDC = ON.

[mattstolte]

Re: Vizio E470VL NO Backlight help

'I on/off .75v[ATTACH]' Inverter on/off is too low, <1VDC = OFF, >2.5VDC = ON.

Power supply or main board fault?

[budm]

Re: Vizio E470VL NO Backlight help

https://www.badcaps.net/forum/showpo...56&postcount=1

[mattstolte]

Re: Vizio E470VL NO Backlight help

So I'm kind of confused. I know the main sends these signals to the psu to turn on. I have some boltages but not all. So is main bad? Or is main sending its signal but power supply is not producing enough voltage?

[budm]

Re: Vizio E470VL NO Backlight help

The main signal is not sending enough Voltage level, it has to be >2.5V for the Backlights circuit to turn on. You can try forcing on the backlights using resistor but you MUST disconnect the BL-ON wire going back to the main board FIRST.
Think about your car, will your car start with 6V?

[mattstolte]

Re: Vizio E470VL NO Backlight help

The main signal is not sending enough Voltage level, it has to be >2.5V for the Backlights circuit to turn on. You can try forcing on the backlights using resistor but you MUST disconnect the BL-ON wire going back to the main board FIRST.
Think about your car, will your car start with 6V?

Now is there a certain component on that main board that is responsible for this that I can change

[budm]

Re: Vizio E470VL NO Backlight help

The problem can be caused by bad Voltage regulator IC, BL-ON switched Transistor that switch HI and LO which is controlled by the controller IC, bad caps, bad EEPROM, bad connections, etc.
So unless you have the diagram to show the details how the BL-ON signal is generated then you just have to start looking at all those parts on the board I mention above

[mattstolte]

Re: Vizio E470VL NO Backlight help

bud where can I get diagram for this so I can check components 3647-0292-0150 even if I have to pay somewhere for it it fine, im sick if swapping boards I need to learn component repair

[budm]

Re: Vizio E470VL NO Backlight help

bud where can I get diagram for this so I can check components 3647-0292-0150 even if I have to pay somewhere for it it fine, im sick if swapping boards I need to learn component repair

I have no idea where you find one.

[mattstolte]

Re: Vizio E470VL NO Backlight help

I have no idea where you find one.

I recently bought a new bk precision esr/dcr meter and I found 2 caps on the main that are shorted and high esr. The metal can smd caps. I'm going to try to replace them. I have never changed out these type of caps. Any hints for switching these type

[triplefour]

Re: Vizio E470VL NO Backlight help

did you ever replace the caps? did it fix the tv?? so tired of these dead ends

[Anthony M]

Re: Vizio E470VL NO Backlight help

Hi all I don't know how to create a thread so I am piggybacking here , I apologize . I have a vizio tv E470VL. Recently the screen went black and I only get sound. I did a flashlight test and I can see images. I was told it could be either a bad power supply led board or bad led strips in the screen itself. How can pinpoint which is th e problem to see if it's worth fixing. Thanks Anthony M

[budm]

Re: Vizio E470VL NO Backlight help

Do you have good Meter with good battery in it for testing DC Voltage?
We will need good straight shot pictures of the power supply board and the closed up pictures around the connectors of the power supply board so we can clearly see the labels for each pin of the connectors.
Testing Voltages is the first step at this point.

[Anthony M]

Re: Vizio E470VL NO Backlight help

I have a voltage meter to test outlets it also can test ohms and continuity . I can take some pics and post

[budm]

Re: Vizio E470VL NO Backlight help

We need the pictures so we can see what we are dealing with, and with the pictures that show the pins' name then we can tell you what to test.

[Anthony M]

Re: Vizio E470VL NO Backlight help

Pics

[budm]

Re: Vizio E470VL NO Backlight help

https://www.badcaps.net/forum/attach...4&d=1491418312
So with the connector is still in place:
1) TV is pluggeg into the outlet but not turn on yet.
2) Black probe on the metal chassis.
3) Red probe on each one of those pins on the connector (you may need skinny probe to make contact with the terminals), report the DCV reading of each pin in this format:
TV OFF
DIM = ??? V
LAMP = ??? V
I-ON/OFF = ??? V
so on and so on

4) Activate the power switch and repeat the same procedure in #3
Just remember one thing, wrong DATA can lead to wrong troubleshooting path.
Make sure your meter is good and has good batteries.

[Anthony M]

Re: Vizio E470VL NO Backlight help

TV Off. TV On
DIM. 0. 3.3
Lamp. 0. 0
I-On/off. 0. 3.3
PS_On. 0. 2.3

12V. 0. 12.3
0. 12.3
0. 12.3

SGND. 0 0
0. 0
0. 0
0. 0

+5VSB. 5.2. 5.2
5.2 5.2
5.2. 5.2

[vinceroger69]

Re: Vizio E470VL NO Backlight help

Hi all I don't know how to create a thread so I am piggybacking here , I apologize . I have a vizio tv E470VL. Recently the screen went black and I only get sound. I did a flashlight test and I can see images. I was told it could be either a bad power supply led board or bad led strips in the screen itself. How can pinpoint which is th e problem to see if it's worth fixing. Thanks Anthony M

Looking at the psu this is not a led set it uses ccfl/eefl tubes i think so may be a faulty tube/wiring issue as your viltages look ok but budm will confirm