Vizio E470i-A0 no power LED, doesn't power on

[shortvent]

Just picked up a Vizio E470i-A0, but when power is connected, the standby LED does not power on, and pressing the power button does nothing. No lights or activity come from the TV or any LEDs on the front of the TV. Obviously the LED backpanel doesn't come on and the TV does not appear to "boot up".

I checked the voltage on pins 1 & 2 of CN201 and got 5V on each. I also checked the two white fuses on the power board, and neither had any resistance on them.

Seems like an issue with the power board, but it'd be great to repair it rather than just buy a new one.

Power board is 0500-0614-0270, mainboard is 3647-0852-0150(2B).

Any suggestions are appreciated! Thank you!

[R_J]

Re: Vizio E470i-A0 no power LED, doesn't power on

What voltage do you have on CN201, PS-ON/OFF pin when you press the power button?

[shortvent]

Re: Vizio E470i-A0 no power LED, doesn't power on

What voltage do you have on CN201, PS-ON/OFF pin when you press the power button?

From the diagram on the board, it looks like pin 8. I used the back shield for ground and tested pin 8, but no voltage change when I pressed the power button.

[budm]

Re: Vizio E470i-A0 no power LED, doesn't power on

So the power supply board is not getting the PS-ON (CN201 pin 8) from main board to turn on the rest of the power supplies. How about BLU-ON/OFF (CN201 pin 9), does it change state when turn the TV or and off?

[shortvent]

Re: Vizio E470i-A0 no power LED, doesn't power on

What voltage do you have on CN201, PS-ON/OFF pin when you press the power button?

My apologies, my ground cable wasn't secure so I went and re-measured.

PS-ON/OFF - 0v before hitting the power button, then jumps to 3.3v after pressing power.

BLU-ON/OFF behaves the same. 0v before hitting the power button, then jumps to 3.3v after pressing power.

I went ahead and did a flashlight test, and I do get "no signal" on the screen, but no backlight and no power LED. I also see red light from the toslink port.

Thanks again for your help!

[nomoresonys]

Re: Vizio E470i-A0 no power LED, doesn't power on

So what are the rest of the voltages on the connector, still 0 with the good ground?

[shortvent]

Re: Vizio E470i-A0 no power LED, doesn't power on

I actually tore the unit down and found many of the backlight LEDs dead (using three 9v in series). I'm going to try to replace the strips entirely.

They're all in these series:
6916L-1175A
6916L-1174A
6916L-1176A

I'm have most of the equipment required to do SMD & larger repairs, but I don't have an "LED replacement workstation". Any recommendations on doing a DIY setup this are appreciated!

[nomoresonys]

Re: Vizio E470i-A0 no power LED, doesn't power on

https://www.youtube.com/watch?v=NI9wOZKHOVE

[diif]

Re: Vizio E470i-A0 no power LED, doesn't power on

I actually tore the unit down and found many of the backlight LEDs dead (using three 9v in series). I'm going to try to replace the strips entirely.

They're all in these series:
6916L-1175A
6916L-1174A
6916L-1176A

I'm have most of the equipment required to do SMD & larger repairs, but I don't have an "LED replacement workstation". Any recommendations on doing a DIY setup this are appreciated!

I use one of these https://www.aliexpress.com/item/4000308886288.html
I'd guess it's what they use in the shopjimmy device.