Vizio 42" LCD VW42LHDTV10A Will Not Turn On

[budm]

Re: Vizio 42" LCD VW42LHDTV10A Will Not Turn On

This is your board: Vizio 3642-0102-0150 Main Board for VW42LHDTV10A
http://www.shopjimmy.com/vizio-3642-...42lhdtv10a.htm

Picture provided by shopjimmy.

[Derrick8265]

Re: Vizio 42" LCD VW42LHDTV10A Will Not Turn On

Correction...I'm being helped by an "ET" - not an "IT". I'm doing the internet searching for the specific info he's needing, like if a schematic exists on this unit. I don't see a manufacture name on the board either. I'm working on figuring out what kind of format you want via your link. Will get back to you when I know more...

[Derrick8265]

Re: Vizio 42" LCD VW42LHDTV10A Will Not Turn On

Bud, I'm not getting your reply until I post a new message...I don't know why.
Yes, that's my board, and they're out of stock or I probably would have just replaced it - considering my understanding of this kind of small technical work. But, I'm learning some new areas of repairs, which I like, since I like to repair all I have that I am able to fix.

[budm]

Re: Vizio 42" LCD VW42LHDTV10A Will Not Turn On

https://www.badcaps.net/forum/showpo...29&postcount=1

I.E.:
U100 -> pcb designation
AS1117-33 -> line 1 of the IC
0506 -> line 2 of the IC
pin 1 = 0.000
pin 2 = 3.301
pin 3 = 5.001

It can be just one bad LDO IC.

[budm]

Re: Vizio 42" LCD VW42LHDTV10A Will Not Turn On

The OP has U7 as the problem.
https://www.badcaps.net/forum/showpo...1&postcount=32
https://www.badcaps.net/forum/showpo...4&postcount=33

[Derrick8265]

Re: Vizio 42" LCD VW42LHDTV10A Will Not Turn On

Bud - I reviewed the PDF link, but unfortunately do not understand much of it. However, I saw how to numerically identify the pins on these little regulators. So, I hope this will be better for you:

U33:
pin 1 is 2.00v
pin 2 is 3.29v
pin 3 is 5.14v
pin 4 is 3.29v

U7:
pin 1 is 0.02v
pin 2 is 0.90v
pin 3 is 3.29v
pin 4 is 0.90v

U8:
pin 1 is 2.06v
pin 2 is 3.30v
pin 3 is 5.15v
pin 4 is 3.30v

U9:
pin 1 is 0.00v
pin 2 is 1.52v
pin 3 is 3.29v
pin 4 is 1.52v

U2:
pin 1 is 2.80v
pin 2 is 3.33v
pin 3 is 5.13v
pin 4 is 3.33v

Is this the format you were looking for?

[budm]

Re: Vizio 42" LCD VW42LHDTV10A Will Not Turn On

U7:
pin 1 is 0.02v
pin 2 is 0.90v
pin 3 is 3.29v
pin 4 is 0.90v
Bad U7 (Adjustable 1117 series) just like OP.

[Derrick8265]

Re: Vizio 42" LCD VW42LHDTV10A Will Not Turn On

Bud - I'm still not getting you replies to show up until after I post...do you know why that is happening? It's making it hard to follow.
I agree, it looks like U7 is bad. And U33 is outputting at 1.52v. Is that ok for that one? If not, it seems I need to order the repair kit.

[budm]

Re: Vizio 42" LCD VW42LHDTV10A Will Not Turn On

Bud - I'm still not getting you replies to show up until after I post...do you know why that is happening? It's making it hard to follow.
I agree, it looks like U7 is bad. And U33 is outputting at 1.52v. Is that ok for that one? If not, it seems I need to order the repair kit.

But you are showing 3.29V output per your reading in post 46.

U33:
pin 1 is 2.00v
pin 2 is 3.29v
pin 3 is 5.14v
pin 4 is 3.29v

[Derrick8265]

Re: Vizio 42" LCD VW42LHDTV10A Will Not Turn On

Any advice on buying replacements?

[Derrick8265]

Re: Vizio 42" LCD VW42LHDTV10A Will Not Turn On

Yes, for U33. But U7 output is .90v...according to the drawing in the PDF listed 2nd via your link. That showed the #2 pin as the output and #3 as the input. Do I understand that correctly?

[budm]

Re: Vizio 42" LCD VW42LHDTV10A Will Not Turn On

Yes, for U33. But U7 output is .90v...according to the drawing in the PDF listed 2nd via your link. That showed the #2 pin as the output and #3 as the input. Do I understand that correctly?

Middle pin (or big tab on top) is the out put pin pin 2, so it is bad because you have only 0.9V output, so yes U7 is bad which is the same IC that failed for OP.
My post 47.

[Derrick8265]

Re: Vizio 42" LCD VW42LHDTV10A Will Not Turn On

Sorry, I see what you're saying. I should have said U9 - not U33. You're right.
Is U9 output ok where it is at 1.52v?

[budm]

Re: Vizio 42" LCD VW42LHDTV10A Will Not Turn On

Any advice on buying replacements?

https://www.badcaps.net/forum/showpo...91&postcount=7
U7 is the ADJUSTABLE LDO.

You might as well order more than one and also get the rest on the list in case others may fail later on.

[budm]

Re: Vizio 42" LCD VW42LHDTV10A Will Not Turn On

Sorry, I see what you're saying. I should have said U9 - not U33. You're right.
Is U9 output ok where it is at 1.52v?

U9 is the 1.5V Fixed regulator LDO.

[Derrick8265]

Re: Vizio 42" LCD VW42LHDTV10A Will Not Turn On

Ok, I think I'm seeing this now. The pin I called #2 has the same readings as the "big one" opposite the three smaller ones, which I called #4. So, it must be the output...or they both are.

[budm]

Re: Vizio 42" LCD VW42LHDTV10A Will Not Turn On

Ok, I think I'm seeing this now. The pin I called #2 has the same readings as the "big one" opposite the three smaller ones, which I called #4. So, it must be the output...or they both are.

They are both output pins (middle pin and big tab), they are connected together inside the IC.

[Derrick8265]

Re: Vizio 42" LCD VW42LHDTV10A Will Not Turn On

Good on U9, so thank so much for the links. I'll get these coming and repost if all-good. I appreciate your help!

[Derrick8265]

Re: Vizio 42" LCD VW42LHDTV10A Will Not Turn On

Good! One final thing: what's IC stand for and LDO?

[budm]

Re: Vizio 42" LCD VW42LHDTV10A Will Not Turn On

IC = Integrated Circuit.
LDO = Low Drop Out Voltage regulator.
You should cut the LDO LEGS first to make it easier to remove, no need trying to save the old part.
I hope you have 40 Watts or higher soldering iron and be careful not to lose the small resistors connected to pin 1 of the LDO.
Use solder flux!