Vizio E550i-B2E does not power on, power LED fades out

[najel]

Hello all,

I have a Vizio E550i-B2E that I got from a coworker. It failed on him and I have been able to repair a failed TV (LG LCD model) before by changing out capacitors on the power supply. However, I don't think that's the issue with this one, as it is not even two years old.

Symptoms: When I power on the TV with remote or button on TV, the screen stays black, the power LED comes on and stays on for a few seconds, then fades away. After a while, if I press power again, the LED lights up for about a second and goes off immediately (no fading).
I tried the flashlight test, and do not see anything displayed on the screen. However, I am not sure if anything would even be displayed (don't know this TV, I don't even know where the menu would appear etc).

I checked the 5V at the power supply and it's there, so is the 3V Power Supply On when I press the power button. Anything else I should check there?

Photos if the interior are attached. I would appreciate any tips as to what to look for, common issues, etc.


Edit: There is one more board underneath the metal at the middle bottom, I think it's just for sound, but if need be I can remove the shield and take a picture of it as well.

[najel]

Re: Vizio E550i-B2E does not power on, power LED fades out

Hello,

So I did some more reading, unfortunately all the instructions etc I found were for regular LCD not specific to LED lit ones, and I'm not sure what's different. But I found:
Power supply on is 3V when I turn the unit on, 0 when I turn it off, so that seems fine.
5V standby is there
12V is there when switched on
24V is there when switched on (but I measure 20V most likely because I'm using volt meter and don't have a way to test with load?)

So I think the power supply is fine. I would like to test the LED driver board, but I am not sure how to. There are no voltages printed on there or any other labels on any pins. Any advice would be appreciated.

And finally the board under the metal shield of course is not for sound as I thought before but it't the T-Con so I added a picture of it here.

Another thing I tried was plug an audio source into the component input and tried switching through the inputs with the remote. I did not hear anything. But I am not sure if I was flipping through the inputs correctly or if I got them all, since I can't see a menu.

[SLK001]

Re: Vizio E550i-B2E does not power on, power LED fades out

The on light is supposed to act like that. Look for cracked joints between the power supply board and the LED controller.

Search the forum for E550i-B2.

[Walter walker jr]

Re: Vizio E550i-B2E does not power on, power LED fades out

Check the driverboards for dislodgement. on the two i repaired seems driver boards became un seated and where making contact with speakers grounding them. again thank u guys im always grateful for the fat(knowledge) u put on my head while opening my eyes. i just headlocked my electrical specialty degree plus 4 other certificates that coincide with my field. shortly before that, in 2016 opened (out the mud) the first tv repair shop in my end of texas and you guys have helped me grind through the struggle. you guys are beast and what im really striving to be like. Badcaps for prez

[johniwad]

Re: Vizio E550i-B2E does not power on, power LED fades out

I recently came into possession of the same model TV with similar issue. After turning on it then turns off seconds later with power LED fading out. I opened and inspected the boards for cracked solder joints but found none. I've also re soldered the connection between power supply and LED driver board for good measure but made no difference. I believe something else is going on.