Vizio E420i-A0

[eagle00799]

I have this Vizio with sound but no backlights, When I check voltages going to led's I get 130V when turned on but it drops and settles at 65v on the LED1+ and LED2+ terminals. The LED1- terminal will hit 83v and drop to 21.5v and the LED2- will start about 150MV and climb to 199MV and start over, This is with the led's plugged in.
With the led's unplugged the LED1+ and LED2+ will react the same but the - terminals settle at about .273volts.
Is it safe to assume I have an LED issues here?

[CapLeaker]

Re: Vizio E420i-A0

[eagle00799]

Re: Vizio E420i-A0

So now after testing and determinating which one and how many are bad can the individual led's be purchased somewhere or do they have to be purchased in strips? Are there any good known suppliers?

[budm]

Re: Vizio E420i-A0

next step will be taking the panel to see what kind of LED strips are being used on the board. I forget that you can buy the LG Innotek LED for the replacement, I forget the P/N.

[eagle00799]

Re: Vizio E420i-A0

I have 3 bad led's out of 50 on 3 different strips. I was under the impression that if 1 led went out the backlights would not come on. Must not be true?
Also if I buy 1 strip I should be able to remove 3 led's and replace them instead of buying 3 strips correct? Or how can I figure out the part number so I can order just led's from LG or another source?

[dick_barton]

Re: Vizio E420i-A0

There are videos referred to on this site showing how to remove LED's and fit them in place of burnt out or shorted Leds. There's also discussions on stacking them.

https://www.youtube.com/watch?v=0uBhca7zyXI&app=desktop

[budm]

Re: Vizio E420i-A0

If all the LEDs are connected as one large string using ONE LED driver then if one goes open circuit then the whole string will be dead, in this case you will NOT see the backlights flash on for seconds.
Then you can have more than one LED driver circuit (you can have up to 12 drivers or more), so in this case you may see the backlights flash flash on for seconds due to the not all the strings are bad.
All of this is based on good LEDs drivers are OK.

[eagle00799]

Re: Vizio E420i-A0

Ok I see how to replace but would sure like to replace with new not used led's.