Vizio GV42LFHDTV10A no pic, no sound, wont shut off

[budm]

Re: Vizio GV42LFHDTV10A no pic, no sound, wont shut off

I can tell if it is fixed or adjustable or not by looking to see if it has resistors network between pin 1 (adj/gnd) and circuit ground, and another resistor between pin 1 and pin 2 (output). You do not want go higher voltage since it may damage the circuit, have to verify.

[StingRay1971]

Re: Vizio GV42LFHDTV10A no pic, no sound, wont shut off

If you were to look at Post 39 in this thread, does that give us our answer?

[budm]

Re: Vizio GV42LFHDTV10A no pic, no sound, wont shut off

"U7 pin 2 = 0.99v - s/b 1.28v - BAD"
Per post 39, the output should be 1.28 (1.25Vref + pin 1 of .05~.03V), so it is adjustable regulator.
See post 12, 14 also.

[StingRay1971]

Re: Vizio GV42LFHDTV10A no pic, no sound, wont shut off

"U7 pin 2 = 0.99v - s/b 1.28v - BAD"
Per post 39, the output should be 1.28 (1.25Vref + pin 1 of .05~.03V), so it is adjustable regulator.
See post 12, 14 also.

Does that mean this would be the part I need to buy:

http://www.digikey.com/product-detai...29-1-ND/586229

Looks like that is what BigDaddy purchased for U7 in his post!

thanks again for helping so far.

[budm]

Re: Vizio GV42LFHDTV10A no pic, no sound, wont shut off

That is OK, this is what I use and stock (see list on post 7):
http://www.digikey.com/product-detai...SCT-ND/1967218

[StingRay1971]

Re: Vizio GV42LFHDTV10A no pic, no sound, wont shut off

That is OK, this is what I use and stock (see list on post 7):
http://www.digikey.com/product-detai...SCT-ND/1967218

I didn't see a list posted on post 7 in this thread:

BUT this is what I did:

I ordered:

1.) Ordered 5 of Part: 497-1229-1-ND
http://www.digikey.com/product-detai...29-1-ND/586229

2.) Ordered 5 of Part: NCP1117STAT3GOSCT-ND
http://www.digikey.com/product-detai...SCT-ND/1967218

3.) Ordered 5 of Part: AP1117E18GDICT-ND
http://www.digikey.com/product-detai...ICT-ND/1301520

I ordered 5 just because it was cheap and to have extras in case I make any mistakes. The first two look like there exactly the same as you mentioned in your previous post, both are ADJ and should do the trick for U7, I Hope.

I saw BidDaddy in post 39 order a 2 of a FIXED AP1117E18GDICT-ND , but not sure for which one this goes too.

I also ordered: ChipQuik SMD1 Low Temperature Removal Kit and Aven AA Tweezers.

Hopefully I receive these parts on Saturday, if they come on Monday I'll be out of town for a week on business and have to continue Aug 12th. But if i receive them Saturday i should be good. I paid extra for shipping and if's shipped in the morning, I should receive it.

Does this sound good for now?

thanks

[StingRay1971]

Re: Vizio GV42LFHDTV10A no pic, no sound, wont shut off

Good News!!!!!

Replaced my bad U7 with the part 1 of my order and it's working like a charm again!


thanks for the help!!!!!!


StingRay

[vinceroger69]

Re: Vizio GV42LFHDTV10A no pic, no sound, wont shut off

Good News!!!!!

Replaced my bad U7 with the part 1 of my order and it's working like a charm again!


thanks for the help!!!!!!


StingRay

thanks for posting the fix.

[budm]

Re: Vizio GV42LFHDTV10A no pic, no sound, wont shut off

Thanks for the follow-up and good job fixing it. BTW, the list is in this thread:
https://www.badcaps.net/forum/showth...999#post300999

[blkdragon987]

Re: Vizio GV42LFHDTV10A no pic, no sound, wont shut off

Hi I have read this whole thread and want to be certain what my problem is so I am just posting my findings so someone more knowledgeable than me can tell me what to replace and what to replace it with.
I wasn't sure which direction to number the pins so if I am wrong forgive me.
U2 5.14 3.3 2.05 AMC1117/FO734J
U7 2.08 1.02 0.02 AMC1117/F0734J
U8 5.17 3.3 2.05 AMC1117/F0734J
U9 2.08 1.19 0.02 K1117S15/726
U33 5.14 2.08 1.29 AMC1117/F0734J
F1 12V both sides
F2 5v both sides

[budm]

Re: Vizio GV42LFHDTV10A no pic, no sound, wont shut off

"U33 5.14 2.08 1.29 AMC1117/F0734J" It is bad, 1.25Vref + 1.29V on pin 1 then the output should be = to 2.54V. Since the output of U33 is fed into the input pin of U9 so it makes U9 looks bad due to too low input voltage.
You need adjustable 1117.

[johnboy1313]

Re: Vizio GV42LFHDTV10A no pic, no sound, wont shut off

Hi I have read this whole thread and want to be certain what my problem is so I am just posting my findings so someone more knowledgeable than me can tell me what to replace and what to replace it with.
I wasn't sure which direction to number the pins so if I am wrong forgive me.
U2 5.14 3.3 2.05 AMC1117/FO734J
U7 2.08 1.02 0.02 AMC1117/F0734J
U8 5.17 3.3 2.05 AMC1117/F0734J
U9 2.08 1.19 0.02 K1117S15/726
U33 5.14 2.08 1.29 AMC1117/F0734J
F1 12V both sides
F2 5v both sides

"U33 5.14 2.08 1.29 AMC1117/F0734J" It is bad, 1.25Vref + 1.29V on pin 1 then the output should be = to 2.54V. Since the output of U33 is fed into the input pin of U9 so it makes U9 looks bad due to too low input voltage.
You need adjustable 1117.

"U7 2.08 1.02 0.02 AMC1117/F0734J" looks bad as well for the same reason.

[budm]

Re: Vizio GV42LFHDTV10A no pic, no sound, wont shut off

Ah, I missed U7.

[johnboy1313]

Re: Vizio GV42LFHDTV10A no pic, no sound, wont shut off

U7 and U33 are both common failures on this model. I fixed one last year with the same symptoms and found both U7 and U33 to have gone bad.

[blkdragon987]

Re: Vizio GV42LFHDTV10A no pic, no sound, wont shut off

So do I need U7 and U33 or just U33. from what I have read on here U33 affects U7 and U9...
Also what all should I get from digikey I have a soldering iron and multimeter but that is about it.

[budm]

Re: Vizio GV42LFHDTV10A no pic, no sound, wont shut off

They are adjustable 1117, see what I use here:
https://www.badcaps.net/forum/showth...999#post300999 post 7
Might as order more than one to make it worth shipping charge and in case you damage them during installation.

[blkdragon987]

Re: Vizio GV42LFHDTV10A no pic, no sound, wont shut off

what else will I need? like the removal kit I read about on here do I need that? and should I just replace U33 or should I replace U7 as well.

[budm]

Re: Vizio GV42LFHDTV10A no pic, no sound, wont shut off

Put in U33 first and then check the voltages again. If you have never done SMD repair before and do not have 50~60 Watts good soldering iron then it will not be easy and you can end up damaging and dislodge the components on on pin1 and pin 2 of the regulator also.

[blkdragon987]

Re: Vizio GV42LFHDTV10A no pic, no sound, wont shut off

yeah I have never done repair work like this. I normally work on cars I am a Toyota technician

[johnboy1313]

Re: Vizio GV42LFHDTV10A no pic, no sound, wont shut off

add solder to both sides of the regulator until all three pins on the one side are bridged, then alternate the tip, side to side, everytime the solder blob melts, move to the other eventually, the regulator will slide off of the pads.