Vizio E371VL power or inverter issue

[johnnyospot]

I have two Vizio E371VL tv's that were among 4 TV's that went down after a nearby lightning strike.
When I plug the set in, the Vizio logo glows orange. When I power the set on, the logo turns white, but there is no picture or sound. I do not see the backlights working either. The only way to turn the set off is to unplug it.

Fuses all test ok.

I measured the large Cap, and it had 391V, all the capacitors look fine... in fact I don't see any heat damage or any component damage at all to indicate a problem...

On the ribbon I had

VBR_B....................3.23V
STATUS...................0.0V
INV ON/OFF.............0.0V
REMOTE ON/OFF.......3.23V
12V.........................12.08V
12V.........................12.08V
12V.........................12.08V
GND........................0.0V
GND........................0.0V
GND........................0.0V
GND........................0.0V
5.1VSB....................5.0V
5.1VSB....................5.0V
5.1VSB....................5.0V

It seems there is a problem in the inverter somewhere, but what should I look for and on which board? as best I can tell it doesn't appear to be the EEPROM problem that seems to come up, or the Capacitors getting fried, but I could be totally wrong...

Any thoughts?

Thanks in advance to all!

[budm]

Re: Vizio E371VL power or inverter issue

"INV ON/OFF.............0.0V" The main board is not sending the on command to turn on the backlights so main board is not functioning.

" The only way to turn the set off is to unplug it." That means you have problem some where on the main board.

[pocketwatch62]

Re: Vizio E371VL power or inverter issue

Check regulator up13 on the main board..

[CapLeaker]

Re: Vizio E371VL power or inverter issue

... and or there may be a bad surface mount cap that has physically no bad sign from the outside.

[johnnyospot]

Re: Vizio E371VL power or inverter issue

up13 measures...

IN.....3.29V
OUT...1.19V
ADJ...0.0V
tab....1.19V

any suggestions as to which Surf Mount Cap 's to look at? I'll start looking at all of them, but if theres any to narrow it down, I won't complain, lol!

Thanks again for the help folks!

[budm]

Re: Vizio E371VL power or inverter issue

What numbers and letters are printed on that U13? There are more than one 3-pin Voltage regulator CIs on that board that should be checked.
We need what are printed on the ICs so we can tell what the Voltage output should be.
SJ sells EEPROM for this model so that can be the problem.
http://www.shopjimmy.com/catalogsear...q=Vizio+E371VL

[johnnyospot]

Re: Vizio E371VL power or inverter issue

I see 3 regulator IC's on the main board...

UP13...AX1007
-12
2051

IN.....3.29V
OUT...1.19V
ADJ...0.0V
tab....1.19V

UP3....AX1007
1462

IN......3.28V
OUT....1.48V
ADJ....0.23V
tab.....1.48V

UP14...AX1008
12101

IN.....5.15V
OUT...3.29V(this tab not connected to board, seemingly intentionally)
ADJ...2.04V
TAB...3.29V

I looked up the Datasheets, and if I understand things correctly, then it sounds like UP14 is definitely good, and either UP3 or UP13 is bad... and I'm guessing its UP13...

Does that make sense? And if that is the bad one, is there something else I should look for that goes with it or, just replace UP13?

[budm]

Re: Vizio E371VL power or inverter issue

U13 (1.2V fixed reg) = 1.2V, OK (you are getting 1.19V)
UP3 (adj reg) = 1.25 Vref + 0.23Vadj =1.48Vout = OK
U14 (ADJ REG) = 1.25Vref + 2.04Vadj =3.29Vout = OK.

So it is not due to these 3 regulators.

[johnnyospot]

Re: Vizio E371VL power or inverter issue

Hmmm... I don't think it's the EEPROM, or at least not just the EEPROM, as the backlights are not working at all, and they should be working if it was just the EEPROM...
Looks like more testing to be done...

Or is a reflow a good next step? I've never done it before, but I do have access to a high end oven that I could try it...
Any suggestions as to where to get best/most detailed directions? is it better to try with a heat gun, or oven?

From what I've read, it looks like wrapping the thing in foil except for the main processor in the middle and doing it in the oven might be the way to go...

[budm]

Re: Vizio E371VL power or inverter issue

Well, if you understand what the TV needs to have the backlights comes on then you will understand why I am saying you have main board problem.
Right now the main board is not sending the ON command to turn on the backlights, if the EEPROM is corrupted (which you have no way to test that EEPROM), or the processor is bad, or etc. then you will not get the command signal.
You need to have PS_ON, BL_ON, PWM dim or A dim.

Post 1 "INV ON/OFF.............0.0V" So how do you think you will get the backlights when the command signal is at 0V?

[johnnyospot]

Re: Vizio E371VL power or inverter issue

Well, if you understand what the TV needs to have the backlights comes on then you will understand why I am saying you have main board problem.
Right now the main board is not sending the ON command to turn on the backlights, if the EEPROM is corrupted (which you have no way to test that EEPROM), or the processor is bad, or etc. then you will not get the command signal.
You need to have PS_ON, BL_ON, PWM dim or A dim.

Post 1 "INV ON/OFF.............0.0V" So how do you think you will get the backlights when the command signal is at 0V?

I totally agree it's a main board problem... I just tried the 2 AAA batteries test on the INV ON/OFF pin and it turned the back lights on... so I need to trace the flow back from there-- somewhere on the main board is the problem, it's just that the usual suspects are apparently not guilty so far... I just found another thread...
Vizio VW37 Power Supply PSON working but no 12v or 24v output ... I haven't finished reading through it yet, but so far it seems to be the same problem but on an older model... hoping I can find the solution there and apply it...hoping, lol!

[budm]

Re: Vizio E371VL power or inverter issue

Those older Vizios are know for having bad regulators problems, the newer E series have EEPROM problem.

[johnnyospot]

Re: Vizio E371VL power or inverter issue

Those older Vizios are know for having bad regulators problems, the newer E series have EEPROM problem.

I wish I could just replace the EEPROM... but hesitate as it says under the details for the new EEPROM Chip from Shopjimmy.com...

Symptoms EEPROM replacement CAN NOT Fix:
- TV turns on but has NO backlight
- TV turns on AND backlights are on, but has no video display at all
- HDMI issues
- Audio issues

[budm]

Re: Vizio E371VL power or inverter issue

You can replace the main board then.

[johnnyospot]

Re: Vizio E371VL power or inverter issue

To update anyone interested,
I finally got my hands on a replacement Main Board. I tried to reflow the main chip, just to see what would happen, but suspect I need better equipment to do that, as it didn't help any. The new board fixed the problem however, so the challenge is finding another for the second TV. Thanks to all for the help!

[budm]

Re: Vizio E371VL power or inverter issue

Thanks for the follow-up.

[Sevenqi]

Re: Vizio E371VL power or inverter issue

I fixed the same TV recently, it's the fuse F1 on the main board broken, replace the fuse everything works.