Vizio E320i-a0 no backlights, flashlight test good.

[adam3303]

Please bare with me. I'm very much a novice at this kind of thing. Only swapped out some leaky caps on some lcd monitors in the past. Bought this tv cheap. Figured it would be pretty easy to diagnose. TV powers on, but no visible display. Using the flashlight trick I can see the Vizio setup menu. Don't have a DMM yet, but it is on the way. I'm curious if someone could point me in the right directions on how to measure the voltages both coming from the power board and the voltages on the main board. I somewhat understand what to look for, but the lack of pins coming from the power has me unsure of what voltage I should expect to read and what I should look for on the main board. I'm assuming that my problem is on the main board (maybe voltage regulator or something). Just a guess without a meter though. Any help is greatly appreciated. Full model number is Vizio E320i-a0. Just an F.Y.I. to a moderator, I posted this once in Troubleshooting computer displays by mistake and didn't or couldn't move the thread to the right location. I should have just deleted it and started over.

[adam3303]

Re: Vizio E320i-a0 no backlights, flashlight test good.

Sorry I haven't got back to this quicker. Been busy and finally got a meter. Voltage tests are as followed:

all pins top to bottom and left to right. Color coded.

Yellow DC in

Power off: (standby)
pin #1 - 23.92v
pin #2 - 23.92v
pin #3 - 0.0v \ continuity to ground
pin #4 - 0.0v \ continuity to ground

Power on:
Same as power off (standby)

red
Power off:
Pin #1 - 23.79v
Pin #2 - 5.58v

Power on:
Pin #1 - 39.0v - 39.52v fluctuates
Pin #2 8.3v - 8.76v fluctuates

I am absolutely sure these two wires (top of picture) (black & white) go to the led back light strips.

orange
Power off:
Pin #1 - 3.947v
Pin #2 - 4.936v
Pin #3 - 0.0v continuity with ground
Pin #4 - 2.678v
Pin #5 - 0.0v
Pin #6 - 0.0v

Power On:
Pin #1 - 3.947v
Pin #2 - 4.926v
Pin #3 - 0.0 ground
Pin #4 - 2.669v
Pin #5 - 3.322v
Pin #6 - 3.322v

Davi.p,

The items you had me check https://www.badcaps.net/forum/showth...ighlight=e320i . I am unsure of exactly how to test. The diodes purple all seemed to test at .154 "black probe to cathode side" and reverse "red probe to cathode side" would cause the meter to steadily climb to OL. I did test these in circuit.

The two items in pink are marked APM1110N. I believe these are N channel Mosfets. I do not know how to test these or what to look for.

The inductors blue and green all "rang" out with corresponding colored pins. The IC between them is marked TAS5707L. I believe this to be a power amplifier for the speakers.

One other item that I checked is what I believe to be voltage regulator marked in black on the bottom of the picture.
It is marked:

???3NF
1117

Pin #1 - 2.058v
Pin #2 - 3.305v
Pin #3 - 4.971 (power off) 4.955v (power on)
If this is a adjustable regulator then the 1.25v difference between Pin #1 and #2 mean it's good?

Any help on where to go, what to test (and how to test)or what looks wrong or right is greatly appreciated.

[ecking767]

Re: Vizio E320i-a0 no backlights, flashlight test good.

I have work on this model Vizio, and I found bad LED strips inside the panel, the LED voltage is around +40 voltage which is good. you will need to check out those LED's inside the panel.

[adam3303]

Re: Vizio E320i-a0 no backlights, flashlight test good.

Thanks for the reply. I have removed the strips, but was unsure of how to test them since the voltage was that high. I guess next time I could just use a 24v power supply and see if i get any light from the leds? I have a new set ordered from Ebay for 12 bucks. Says they are tested good, so we'll see.
Thanks again.

[ecking767]

Re: Vizio E320i-a0 no backlights, flashlight test good.

Thanks for the reply. I have removed the strips, but was unsure of how to test them since the voltage was that high. I guess next time I could just use a 24v power supply and see if i get any light from the leds? I have a new set ordered from Ebay for 12 bucks. Says they are tested good, so we'll see.
Thanks again.

you can test your LEDs by using your multimeter, set your meter to test diode function. Then make contact using probes (red and black) on each LED, the LED should light if good or if you have your probes in the right direction on the LED. Not sure about the probes direction then measure each LED in both direction.

[adam3303]

Re: Vizio E320i-a0 no backlights, flashlight test good.

The replacement LED's brought it back to life. Thanks.

[rlega]

Re: Vizio E320i-a0 no backlights, flashlight test good.

you can test your LEDs by using your multimeter, set your meter to test diode function. Then make contact using probes (red and black) on each LED, the LED should light if good or if you have your probes in the right direction on the LED. Not sure about the probes direction then measure each LED in both direction.

Hello everyone,

I'm having an issue with a Vizio 320-A0 that I have and it got hit by lightning. I thought it was going to be an easy fix so I deviced to work on it. At the beginning I tried to fix the power supply myself, but did not work. I still could not get power to the tv, not even the white power light.

https://www.badcaps.net/forum/showthread.php?t=39101

budm suggested to buy the power supply and luckily I found one at an electronic shop. When I connected it, it was still the same as it was, not even the light on the front of the tv was on.

So I ordered a mainboard, arrived, now I see the front light, but the TV was not turnining on. That's what I thought, until I use a flashlight to check the screen, and I noticed the screen was ON and upside down, still no backlights.

I took the TV apart and I see the LED strips that someone mentioned before, but how to test those?

Can someone give me some advice how to check them?

https://www.badcaps.net/forum/attach...1&d=1407015318

https://www.badcaps.net/forum/attach...1&d=1407015318

https://www.badcaps.net/forum/attach...1&d=1407015318

Perhaps it is the mainboard I ordered it arrived DOA, but I want to check the LED strips before making any other decision.

Thanks