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Crumbtrail TV Forums: TV Equipment: TV Repair Forum:
42" Vizio E421VO does not power on- no lights. Technical.

 

 


Techie117
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Mar 30, 2012, 5:15 AM

Post #1 of 17 (20738 views)
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42" Vizio E421VO does not power on- no lights. Technical. Can't Post

Hello tv-forums

I'm a fan of Ron.M's work here!

I searched for "E421V" but there appears to be no threads for this relatively new TV. I figured I'd go ahead and start a thread about mine in hopes that it will help myself and others fix their broken Vizio. I'd like for this thread to get technical but understand I may be shooting in the dark.

Warranty status: It's not covered under warranty because I lost the receipt and Walmart failed to find any receipts of our purchase from last December because we paid cash :o

Model #: E421VO
PSU part #: 3PCGC10017A-R
Main board part #: 0171-2271-3276

The TV will not power on. No lights. Not even the orange light will power on. I have tried multiple power cords on multiple outlets. The power supply board has been replaced with a tested working one and nothing changed. I am pretty confident it is the main board that is bad but they seem to be sold out everywhere. I would like to fix the main board myself anyway, as I have experience soldering and am hoping it's something as simple as one of the tiny 3-pronged voltage regulators that is bad. The t-conn board appears to be built-in to the main board but I'm no expert.

I have tried Vizio's suggestion of unplugging the power cord, holding down the power button for 45 seconds then releasing the power button and plugging the power cord back in to try again. Of course it did not work :D

I have carefully examined the entire board (top and bottom). No capacitors are bulging or appear to be bad and there are no obvious burn marks of any kind. Everything appears like new except perhaps this tiny, tiny, flat, black, ~5mm by 5mm (1/5" by 1/5") chip that has 7 legs on each side (14 total), which appears to have a tiny amount of cloudy white stuff on top of it. It does not rub off with a fingernail. I don't think it is the problem but who knows. Please SEE PIC 1

I have tested the voltages the power supply board is supplying the main board with the cable both, plugged in and not plugged in to the main board, with the same results. The 3 pins that should read 5.2v are reading 5.25v so good to go there. The 3 pins that should read 12v are reading 0.00v (Even after pressing the power button). The VBR_B, STATUS, and both ON/OFF pins read 0.00v (Even after pressing the power button). The speaker terminals and 3 pins on the bottom of the board going to the front LED also read 0.00v. In fact, I'm not reading any voltage anywhere on the main board I've tested EXCEPT on what appears to be a tiny rectangular fuse-like thingy that says "IE3A" which is located right next to where the power comes into the main board. The other tiny rectangular fuse-like thingy, which is next to the other one, says "IE5A" and reads 0.00 volts. Perhaps this is the cause. If so, does anyone know the correct terms to google? I have tried '"ie5a" lcd' with no success. Do you know what this little guy is called? SEE PIC 2

From what I understand (Though I could be wrong), the reason the power supply board (PSU) is not sending 12 volts through the cables is because it is not receiving the "turn on" signal from the main board.

Here are some photos that will make it much easier to picture:

PIC 1 Cloudy white stuff on top of the tiny tiny chip


PIC 2 Voltage readings


Thoughts?

Thanks in advance for your help :-)


(This post was edited by Techie117 on Mar 30, 2012, 11:15 AM)



Techie117
New User

Mar 30, 2012, 10:42 AM

Post #2 of 17 (20697 views)
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Re: [Techie117] 42" Vizio E421VO does not power on- no lights. Technical. [In reply to] Can't Post

Grazie, Talhajiya!

Perhaps this seed will see plenty of sun and water

Ut Infra At Supra


jts1957
Veteran


Mar 30, 2012, 2:36 PM

Post #3 of 17 (20691 views)
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Re: [Techie117] 42" Vizio E421VO does not power on- no lights. Technical. [In reply to] Can't Post

Not after we put in our parking lot. Crazy


-------------------------
Location: Far, Far Away


Ron.M
Veteran


Mar 31, 2012, 6:34 PM

Post #4 of 17 (20673 views)
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Re: [Techie117] 42" Vizio E421VO does not power on- no lights. Technical. [In reply to] Can't Post

 

Techie117;....





Quote
I'm a fan of Ron.M's work here!


Thanks for the kudo's....



But , sorry to say, I do not work on LED,LCD or Plasma TVs...
We have some GREAT techs here & I'm sure they will help you...


GOOD LUCK...Sly....


Have a GREAT day & weekend....Sly....


Later..Ron.M....Cool....
Veteran & Retired TV technician


Techie117
New User

Apr 1, 2012, 12:56 AM

Post #5 of 17 (20660 views)
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Re: [Ron.M] 42" Vizio E421VO does not power on- no lights. Technical. [In reply to] Can't Post

Hi Ron

Good to hear!... and thanks for your help in fixing my CRT... I'm pretty sure it was one of your posts that helped me a while back with a TV I had... I remember your name Cool


Ron.M
Veteran


Apr 1, 2012, 2:25 AM

Post #6 of 17 (20653 views)
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Re: [Techie117] 42" Vizio E421VO does not power on- no lights. Technical. [In reply to] Can't Post

 

Techie117;....


Quote
I remember your name Cool

HMmmm...Sam Malone at Cheers ???

Sorry to say this , but you had to have had a different name back then...
I don't remember a "Techie117" & the records show that that name first appeared here on Mar,29,2012 ...
That would be this thread ONLY...

It is STILL nice of you to remember me & for that , I THANK you...

I'm going back to the bleachers & leave it to the others to help you...


Have a GREAT evening....Sly....

Later...Ron.M....Cool...
Veteran & Retired TV technician


Techie117
New User

Apr 1, 2012, 2:48 AM

Post #7 of 17 (20650 views)
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Re: [Techie117] 42" Vizio E421VO does not power on- no lights. Technical. [In reply to] Can't Post

Lol I was a lurker back then. It was a while ago. I should have created an account back then to thank you


Techie117
New User

Apr 2, 2012, 8:39 PM

Post #8 of 17 (20626 views)
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Re: [Techie117] 42" Vizio E421VO does not power on- no lights. Technical. [In reply to] Can't Post

Looks like so far I've struck out with fixing the board. I have found a replacement but the board has extra features such as an extra RCA input on the side and an s-video input on the back. I'm not worried about it physically fitting since my side plate already has pre-cut holes that I can punch out for the extra connectors, but I am worried if the power supply will provide the correct voltages for this main board to work. Does anyone have any insight into this?

Here is the board I have, 0171-2271-3276



and here is the replacement board, 0171-2271-3060




mel
Veteran

Apr 2, 2012, 10:09 PM

Post #9 of 17 (20625 views)
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Re: [Techie117] 42" Vizio E421VO does not power on- no lights. Technical. [In reply to] Can't Post

Shopjimmy.com has this board listed under Vizio P/N 3642-1232-0150/0171-2271-3276 as in stock. It does not look like the connectors at the top of the board on the two boards you show have the same number of pins.


Techie117
New User

Apr 2, 2012, 10:23 PM

Post #10 of 17 (20619 views)
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Re: [Techie117] 42" Vizio E421VO does not power on- no lights. Technical. [In reply to] Can't Post

I just now did a search at shopjimmy for 3642-1232-015 and for 0171-2271-3276

Everything says out of stock


mel
Veteran

Apr 3, 2012, 2:32 AM

Post #11 of 17 (20609 views)
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Re: [Techie117] 42" Vizio E421VO does not power on- no lights. Technical. [In reply to] Can't Post

Sorry about that. One place it says the following items are in stock but another says out of stock. Looks like a popular item.


Techie117
New User

Apr 3, 2012, 2:39 AM

Post #12 of 17 (20606 views)
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Re: [Techie117] 42" Vizio E421VO does not power on- no lights. Technical. [In reply to] Can't Post

It's cool... Yeah they are very hard to find. Since I have two power supplies I'm thinking about just jumping the second tiny rectangular fuse-like thingy on the main board' the one that's not reading any voltage. It's a long shot for sure , but at least I have a backup psu incase the one gets fried Unsure


Techie117
New User

Apr 3, 2012, 2:46 AM

Post #13 of 17 (20603 views)
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Re: [Techie117] 42" Vizio E421VO does not power on- no lights. Technical. [In reply to] Can't Post

Now this is odd... The tiny rectangular fuse-like thingy that was reading 5.2 volts when plugged in is reading infinite resistance on the multi meter when not plugged in... And the other tiny rectangular fuse-like thingy that reads 0.00 volts when plugged in reads no resistance on the multi meter when not plugged in... It's opposite of what a fuse would read. What are these things, some kind of anti-fuse?!?




(This post was edited by Techie117 on Apr 3, 2012, 2:55 AM)


JohnRocks
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Apr 3, 2012, 4:03 AM

Post #14 of 17 (20598 views)
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Re: [Techie117] 42" Vizio E421VO does not power on- no lights. Technical. [In reply to] Can't Post

I think it is Surface-Mount Fuses which are available for addressing a broad range of overcurrent protection applications. Helping to prevent costly damage and promote a safe environment for electronic and electrical equipment, surface-mount chip fuses provide performance stability to support applications with current ratings form 0.5A up to 20A. TE Connectivity also offers the Raychem telecom FT600 fuse for telecommunications applications.
-----------------------------------------------------------------

Rackmount LCD Monitor
USB KVM


Techie117
New User

Apr 3, 2012, 4:33 AM

Post #15 of 17 (20588 views)
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Re: [JohnRocks] 42" Vizio E421VO does not power on- no lights. Technical. [In reply to] Can't Post

John you nailed it... doing a google image search confirms they are surface-mount chip fuses. Any idea why the one that acts blown is the one reading voltage when everything is plugged in? I believe it was reading 5.2 volts on BOTH sides of the fuse... strange


jts1957
Veteran


Apr 3, 2012, 5:53 AM

Post #16 of 17 (20592 views)
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Re: [Techie117] 42" Vizio E421VO does not power on- no lights. Technical. [In reply to] Can't Post

A "good" SM fuse will (with DVM set to measure DC volts & set plugged in and supposedly turned on) read the same voltage on either end referencing ground. A defective fuse will read a voltage on only one end. All this presumes they are in a DC circuit. I can't recall seeing them as part of AC protection circuits.

Of course ALL fuses will read a VERY LOW resistance with DVM set to an ohm or diode scale and your meter will thank you if you keep set unpowered during these continuity tests.


-------------------------
Location: Far, Far Away

(This post was edited by jts1957 on Apr 3, 2012, 5:55 AM)


Techie117
New User

Apr 3, 2012, 6:10 AM

Post #17 of 17 (20594 views)
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Re: [jts1957] 42" Vizio E421VO does not power on- no lights. Technical. [In reply to] Can't Post

I'm going to plug it back in tomorrow and run tests again. Perhaps my initial picture is backwards on the reading of the two fuses. I did run continuity tests with unit unplugged for two days. There's a main board on eBay right now. If I buy it I will definitely run tests and compare to this broken board. Thanks for your input

 
 
 


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