Vizio E371VA Power Problem?

[Mark355]

Re: Vizio E371VA Power Problem?

Will do as soon as I'm home from work. The second pic is to find out if that orange cap is the one that could fail without it showing anything physically.

Thanks for the continued suggestions,

Mark

[selldoor]

Re: Vizio E371VA Power Problem?

Something weird going on with pictures- it is there and was there before your post tom
as I looked at it. - its an ELITE UGGH!! 16v 330uF

[tom66]

Re: Vizio E371VA Power Problem?

Something weird going on with pictures- it is there and was there before your post tom
as I looked at it. - its an ELITE UGGH!! 16v 330uF

Elite caps suck, they are like Capxon... I have too many of them to count in my bad caps bag...

[Mark355]

Re: Vizio E371VA Power Problem?

OK folks, the 12's read 12.2, the 5's read 5.3 and the 24's read 24.8. If by chance the Elite is bad, wouldn't it show in these readings? Probably a stupid question, but hey it's my first rodeo!

Thanks,

Mark

[Mark355]

Re: Vizio E371VA Power Problem?

Here's something weird. Sometimes coming from standby, to power on via the power button. I can hear a faint very high pitched whine just before the screen starts to flash on and off. The whine quits after the screen (backlight) starts to flash. Also there is a blue led light on the board on the far left that flashes with the screen. Didn't know if that was any help or not.

Thanks,

Mark

[budm]

Re: Vizio E371VA Power Problem?

You have correct voltages, but it sounds like you may have problem in the inverter board (bottom left). I would take that out and do some close up inspection and also take good pictures of it.

[Mark355]

Re: Vizio E371VA Power Problem?

Thanks Budm, will do when I get home from work.

Mark

[Mark355]

Re: Vizio E371VA Power Problem?

Here are the pics of the inverter board. Nothing looked out of place to me. But if it is the general opinion that this is the culprit, I'm glad to see that this board is only $42.00.

Thanks for your suggestions and advise,

Mark

[Mr Bill]

Re: Vizio E371VA Power Problem?

Looking at your inverter board it appears Q1, Q3, Q4, Q5 are MDD1752. If that is the correct number then its a N channel mosfet.

One might be shorted out. To check for shorts set your multimeter to ohms and probe the pins per below. (i uploaded a pic of mdd1752 to help identify what each pin is)

G-S
G-D
D-S

If anyone of the measurments is under 30 ohms it may be shorted causing the backlight to flicker on and off.

EDIT:
Also check the transformers for any cold solder joints. Can you post the numbers from the 2 transformers?

[Mark355]

Re: Vizio E371VA Power Problem?

Thanks Mr. Bill,
Here's what I found:

All G-S readings were 9.1

Q1: D-G = 133.1 D-S = 116.1
Q3: Open
Q4: D-G = 134.9 D-S = 117.7
Q5: Open

Transformer No.: L2-EF37-H108228-KD

I hope I read everything correctly.

Thanks,

Mark

[budm]

Re: Vizio E371VA Power Problem?

What Ohm scale did you use on the meter?

[Mark355]

Re: Vizio E371VA Power Problem?

This scale Budm.......how did I screw it up? lol

Thanks,

Mark

[budm]

Re: Vizio E371VA Power Problem?

OK, 200KOhm range, so the MOSFETs are OK.
There is one thing you can do is to check the two yellow caps ESR and the capacitance or juts replace them.
You may have bad inverter board or bad lamp assembly. So you can take a chance on the caps first or try new inverter board.

[Mark355]

Re: Vizio E371VA Power Problem?

Thanks Bud. I'll check those caps tonight. What range should they read?

Thanks,

Mark

[selldoor]

Re: Vizio E371VA Power Problem?

Here is the data sheet for that series. Varying reports on Samyoung.

[Mark355]

Re: Vizio E371VA Power Problem?

I just ordered the inverter board. I hope that's it! I'll let everyone know the results.

Thanks for the help,

Mark

[Mark355]

Re: Vizio E371VA Power Problem?

Well, the board arrived today, didn't take long to determine that that didn't fix it.....bummer. Same flashing backlight and dimming of the Vizio logo. Anything else, or is it to the trash?

Thanks,

Mark

[budm]

Re: Vizio E371VA Power Problem?

Well, back to drawing board.

[Mark355]

Re: Vizio E371VA Power Problem?

Any suggestions?

Thanks,

Mark

[budm]

Re: Vizio E371VA Power Problem?

Not yet, it just does not make sense yet since you do have the 24v for the inverters and PS_ON, BL_ON signals.