Vizio E420-A0 will not turn on!


	FORUM HOME	SEARCH POSTS	WHO'S ONLINE	LOG IN	RULES F.A.Q.

TV Forums: TV Equipment: TV Repair Forum:
Vizio E420-A0 will not turn on!

Print Thread

Killson
New User

Mar 11, 2016, 9:28 PM

Post #1 of 9 (9721 views)
Shortcut

Vizio E420-A0 will not turn on!	Can't Post

Hello,
I have a 3 year old Vizio E420-A0. For a few weeks now I had lots of problems turning the tv on. The power button on the tv should be the only way to turn it on but I would have to press it 3 or more times. Then one day it wouldn't turn on at all. So I opened the tv. All the competitors and everything looked fine. So I tested the voltage to the main board and it was good then I tested the power button and sensor and they where good too. I replaced the main board to see if the problem was there and the tv still hasn't turn on.

When you plug the tv in the power indicator turns on bright and then fades away. Then I try turning on the tv with the remote and side buttons and nothing happens.

My only guess is to try to replace the power supply board to fix it. I would like some with any ideas what is wrong.

Ron.M
Veteran

Mar 12, 2016, 12:35 AM

Post #2 of 9 (9706 views)
Shortcut

Re: [Killson] Vizio E420-A0 will not turn on! [In reply to]	Can't Post

Killson;...

I'm currently working on a Vizio E420i-AO which I believe it's the SAME one you are working on...
It is also not turning on...
Start by going to this thread;=>...
http://www.tv-forums.com/...i?post=161322#161322
Read the whole thread & do the voltage checks that I did...
Go to post #2 that jts1957 has graciously posted a link to ShopJimmy..
Go to the video & follow the steps to read the LED outputs , LED1 & LED 2..
Read VOUT1 & VOUT2 ...
Use chassis ground for the "-" lead on your meter..
Compare your readings with those that are in the video...
Chances are that the power supply is OK...
Mine has 6 (Yes SIX) bad LED strips..
IF you think your LED strips are bad , I have an EASY way to test each strip..

Please post your results & I'll help you further along as best as I can..

Be advised that Vizio does NOT make a Service Manual available to independent techs for that model...

Later...Ron.M... Cool

..
Veteran & Retired TV technician

(This post was edited by Ron.M on Mar 12, 2016, 12:38 AM)

Killson
New User

Mar 15, 2016, 2:09 PM

Post #3 of 9 (9668 views)
Shortcut

Re: [Ron.M] Vizio E420-A0 will not turn on! [In reply to]	Can't Post

Thanks for the response.

I can't turn on the tv so the voltages with the tv plunged in at Vout1 and Vout2 are both 60. So I unplunged the LED leads from the powers supply board and found that when the tv was plugged in Vout1and Vout2 both read 0. So the video says I need to replace the power supply board.

Thanks again for the response and let me know what you think.

Ron.M
Veteran

Mar 15, 2016, 5:41 PM

Post #4 of 9 (9656 views)
Shortcut

Re: [Killson] Vizio E420-A0 will not turn on! [In reply to]	Can't Post

Killson;...

IF you are getting 60 vdc at VOUT1 & VOUT2 , the TV IS turning ON !!!..
You are getting no pix & probably no sound , so you think the TV is not turning on...
WHAT ARE the voltages at Pin #1(LED 1) & Pin #5(LED 2) ???..

Let's restart this...
Let's find out IF the Power Supply IS bad !!!
On the power supply board the are 2 connectors..
In the pix on the right side is the main power connector that feeds the main board etc...
That is CN201 & it has 12 pins...
The other connector is CN301 & has 7 pins..
That is power ONLY for the backlight LEDs...
IF you get voltage there , the power supply IS WORKING !!!..
When the TV is off there are very low volts on LED2 & VOUT2..
Lets determine WHERE the problem IS...
Start by plugging in the TV & do NOT turn it on;;;
Take readings from CN201...
Use the pointy end of your "+" meter probe & stick it into the connectors wire end to get a reading..
Use CARE when you do this so you don't fracture the connector's plastic..
If you look closely at the wire end , you'll see metal on each wire end..
That is where you touch your meter's SHARP pointy end to...
PLEASE post readings here;=>..
TV OFF:=>..
Pin #1 & 2 = ??
Pin #3 , 4 & 5 are ground (case) connections
Pin #6 & 7 = ??
Pin #8 = ??
Pin #9 =??
Pin #10 =??
Pin #11 =??
Pin #12 =n/c

Then press the power button ON the TV ONCE ONLY..
Re-read the same pins & post readings here;=>..

TV ON:=>..
Pin #1 & 2 = ??
Pin #3 , 4 & 5 are ground (case) connections
Pin #6 & 7 = ??
Pin #8 = ??
Pin #9 =??
Pin #10 =??
Pin #11 =??
Pin #12 =n/c

IF you have trouble reading those voltages , please post & I will help you do this...

[URL=http://s772.photobucket.com/user/RonMa/media/Vizio%202A_zpsk6zvjx9o.jpg.html]

Later...Ron.M... Cool

...
Veteran & Retired TV technician

(This post was edited by Ron.M on Mar 20, 2016, 6:36 PM)

Ron.M
Veteran

Mar 20, 2016, 6:29 PM

Post #5 of 9 (9615 views)
Shortcut

Re: [Killson] Vizio E420-A0 will not turn on! [In reply to]	Can't Post

Killson:...

WHAT HAPPENED ???...
I'm still waiting for a reply !!!..
It's been FIVE DAYS since you posted for help !!!
What's going on with you &/or the TV ???...

THANKS !!!..... Smile

Later...Ron.M... Cool

...
Veteran & Retired TV technician

Killson
New User

Mar 23, 2016, 4:48 AM

Post #6 of 9 (9591 views)
Shortcut

Re: [Ron.M] Vizio E420-A0 will not turn on! [In reply to]	Can't Post

Sorry, My tv is at school and I went on spring break and when I got back I had to leave for a track meet for 4 days. I'll most likely take a look at the tv again Thursday or Wednesday. Thanks for caring

Killson
New User

Mar 25, 2016, 3:08 AM

Post #7 of 9 (9562 views)
Shortcut

Re: [Ron.M] Vizio E420-A0 will not turn on! [In reply to]	Can't Post

TV OFF:=>..
Pin #1 & 2 = 5.3
Pin #3 , 4 & 5 are ground (case) connections
Pin #6 & 7 = 70 mv
Pin #8 = 0
Pin #9 = 0
Pin #10 = 1.71
Pin #11 = 1.71
Pin #12 =n/c

TV ON:=>..
Pin #1 & 2 = 5.3
Pin #3 , 4 & 5 are ground (case) connections
Pin #6 & 7 = 11.92
Pin #8 = 3.26
Pin #9 = 0
Pin #10 = 3.36
Pin #11 = 5.24
Pin #12 =n/c

At VOUT1&2 when the tv is off the voltages vary so I cant get a good reading.

VOUT1&2 when the tv is on the voltages is 60v

After hitting the power button once and getting the voltages for the tv being on there is still no pitcher and when I hit the power button again the tv still has the same voltages as it did if it was on. So I'm saying the tv will not turn off.

Ron.M
Veteran

Mar 25, 2016, 4:59 PM

Post #8 of 9 (9517 views)
Shortcut

Re: [Killson] Vizio E420-A0 will not turn on! [In reply to]	Can't Post

Killson;....

There's a problem with the reading on pin #9 (BLU) when the TV is ON !!!
Please recheck that...
I believe that that is for the backlights..
Should read aprox 3.2 vdc when the TV is on...
jts1957 or Repair man may comment on that ...

Also , would like to know what your reading on CN301 (Backlight connector) pins #1 (LED1) & # 5 (LED2) ON & OFF...
On CN201 , pin #10 is OK when on...
Pin #11 is high !!!
Both pins #10 & 11 should read 0.0 vdc when off..
Something is amiss with pins #9 , 10 & 11 readings..
Are you getting sound ???..

Please post results...
Thanks...

Later...Ron.M... Cool

...
Veteran & Retired TV technician

(This post was edited by Ron.M on Mar 25, 2016, 5:03 PM)

Ron.M
Veteran

Mar 30, 2016, 5:52 PM

Post #9 of 9 (9482 views)
Shortcut

Re: [Killson] Vizio E420-A0 will not turn on! [In reply to]	Can't Post

Killson;.....

My patience is wearing thin with you !!!
Time to S#*T or get off the pot !!!

You have 48 hours to get this rolling or I'm history...

Later...Ron.M... Cool

...
Veteran & Retired TV technician

Print Thread

Search for (options)

- Page loaded in: 0.13 s on (CGI/1.1)