E320-A0 - Power LED Fades, Sound, Picture (Without Backlight) LED Issue

[crepiduse]

I have a E320-A0 that I am fairly certain is the backlight strips. All voltages are normal, and getting 33v to LED strips.

Now, on the main strip, input is 33v goes through 5 LEDs, out at the end is 9v.

The first strip doesnt even flicker. The second is very faintly flickering.

I am fairly certain its the LED strips. I can not find replacements anywhere, so is there a way to test this to the individual strips and individual leds?

[budm]

Re: E320-A0 - Power LED Fades, Sound, Picture (Without Backlight) LED Issue

You can test each LED using Diode mode (hopefully your meter can supply enough Voltage to bias on the white LED), or use 3V battery with 100 Ohms resistor to limit the current to test the LED.

[crepiduse]

Re: E320-A0 - Power LED Fades, Sound, Picture (Without Backlight) LED Issue

Correction,

The voltage is coming out of NEG on the end, so it appears to short to ground somewhere. (BAR One)

[budm]

Re: E320-A0 - Power LED Fades, Sound, Picture (Without Backlight) LED Issue

5 x 3.3V =16.5V minimum + Vdrop on the current sensor resistor and PWM MOSFET. You have more than enough due to open circuit Voltage reading without the loads (LEDs).
So start checking each LED.

[crepiduse]

Re: E320-A0 - Power LED Fades, Sound, Picture (Without Backlight) LED Issue

Adding pictures.

[budm]

Re: E320-A0 - Power LED Fades, Sound, Picture (Without Backlight) LED Issue

The hardest part will be trying to get the new replacement LEDs and removing and installing the new LEDs.
You may check with shopjimmy.com to see of they have replacement strips.
This model is known for having bad EEPROM also.
BTW, what DCV do you get measuring between the TWO from the board to the first LED strip?

[crepiduse]

Re: E320-A0 - Power LED Fades, Sound, Picture (Without Backlight) LED Issue

I believe the eeprom to be good, as I have all correct voltages, and led's out. I have replaced the main board with an "assumed bought good" board that came from a working busted panel tv to get the same issue.

using all the part numbers, not even shopjimmy came up with the strips.

how could the eeprom cause the led's to not function with correct voltage?



--Forgive me, what do you mean "what DCV do you get measuring between the TWO from the board to the first LED strip"


.

[budm]

Re: E320-A0 - Power LED Fades, Sound, Picture (Without Backlight) LED Issue

Is this the power supply/led driver board you have?
http://www.shopjimmy.com/vizio-56-04...upply-unit.htm

[crepiduse]

Re: E320-A0 - Power LED Fades, Sound, Picture (Without Backlight) LED Issue

No I have this main board and this power board.

[newtothis]

Re: E320-A0 - Power LED Fades, Sound, Picture (Without Backlight) LED Issue

I have managed to get Amtran LED's from Amtran directly once :

Feilin.chen@amtran.com.tw

Give them an email and see what they say

[crepiduse]

Re: E320-A0 - Power LED Fades, Sound, Picture (Without Backlight) LED Issue

I have managed to get Amtran LED's from Amtran directly once :

Feilin.chen@amtran.com.tw

Give them an email and see what they say

Delivery to the following recipient failed permanently:

Feilin.chen@amtran.com.tw

Technical details of permanent failure:
Google tried to deliver your message, but it was rejected by the server for the recipient domain amtran.com.tw by spam.amtran.com.tw. [211.72.203.8].

The error that the other server returned was:
553 5.7.1 SpamTrap=reject mode, dsn=5.7.1, Message blocked by BOX Solutions (www.box-sol.com) SpamTrap Technology, please contact the AMTRAN site manager for help: (t3MLtIEk022880 ctlusr8012).

[newtothis]

Re: E320-A0 - Power LED Fades, Sound, Picture (Without Backlight) LED Issue

Email has changed then, I will see if I can get an updated one

[newtothis]

Re: E320-A0 - Power LED Fades, Sound, Picture (Without Backlight) LED Issue

it_infra@amtran.com.tw

try that one

[crepiduse]

Re: E320-A0 - Power LED Fades, Sound, Picture (Without Backlight) LED Issue

it_infra@amtran.com.tw

try that one

Seemed to go through. Will see if I get a response. Thank you.

--------

In the mean time, Budm, is there any more on your question so I can continue to diagnose? (I am still looking for a 100ohm resistor that seems to have eluded me.)

[crepiduse]

Re: E320-A0 - Power LED Fades, Sound, Picture (Without Backlight) LED Issue

I cant get any of the leds to light up with 3v 100ohm resistor supplied power
.

[budm]

Re: E320-A0 - Power LED Fades, Sound, Picture (Without Backlight) LED Issue

You try both direction and are you sure you are making contact with the LED's legs?
It can also be dual-LED (two white LEDs connected in series inside) in one body.

[crepiduse]

Re: E320-A0 - Power LED Fades, Sound, Picture (Without Backlight) LED Issue

I tried all the points on the strip. I can not get below the dome without damaging it.

[keeney123]

Re: E320-A0 - Power LED Fades, Sound, Picture (Without Backlight) LED Issue

It looks like in your picture the LEDs are connected in parallel. The power feeding into one strip and at the end of that strip it is jumper-ed to the second strip. It seems also there are test points label. I make out one as TP4. If the cables are disconnected and you take an ohm measurement where the cables plug in are you measuring a short?

[keeney123]

Re: E320-A0 - Power LED Fades, Sound, Picture (Without Backlight) LED Issue

To verify the led's on the strip are connected in parallel you could take the first strip that the power goes into and measure from where the black cable would connect to the black cable on the output connector of the same LED strip, the connector that connects that LED strip to the other LED strip through the cable. You can then do the same for the other colored cable, I guess the other cable that is white or gray. This measurement can be done without any cable connected. If they are in parallel you should read a short on both measurements. But first do the previous procedure to make sure that you do not have a short between the two input pins of the first LED strip.

[keeney123]

Re: E320-A0 - Power LED Fades, Sound, Picture (Without Backlight) LED Issue

Woke up this morning wondering what was I thinking. They drive these LED strips with voltage even though they are a current driven devise so I take back the parallel and say it must be connected in series. I do not know why they don't connect them in parallel so that if one went out the others could still be working. Anyway, the driver circuit should tell a person how they are connected.