Vizio GV42LFHDTV10A no pic, no sound, wont shut off

[organizddisastr]

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

I replaced U33 and thought i was in trouble because i ripped the pads off taking the regulator off. I did a little magic tracing the circuit and BOOM IT WORKS!! Thanks for all your info!!! You guys are the best!!!

[badvztv]

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

I also ended up just replacing U33 without testing anything and it fixed the issue.

Awesome 80 cent fix!

Thanks everyone for the helpful posts!

[electronicsurplus]

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

Hello all, I am trying to diagnose a main board from a vizio GV42LFHDTV10A which has backlight but, no picture. I tried a similar board from a different model television and the television worked but, had garbled and double video, which told me that the power supply was functioning properly. I already checked both of the fuses on the main board and, they checked ok. I am stumped from there. I am a NOOB and, do not know how to check the Regulators or Mosfets. ANY help would be greatly appreciated. I have unsuccessfully tried to find a replacement board but, am unable to find a board that cost less than the entire tv is worth.

Can anyone help please?

I have a service manual for the set but, that does not help much since, there are no schematics included.

Thank you
John

Also, being an Electronic Recycler, we do have many complete working boards in stock EXCEPT for this one

[selldoor]

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

Hi electronicsurplus, Ok, you are currently working on a main board from a vizio GV42LFHDTV10A and you feel that the problem with it might be U33.

You are unsure how to test it or what it is and are unable to read the part numbers off it. (Sometimes they become clearer if rubbed with Isopropyl alcohol on a Qtip.)

Having established what it is, you want some guidance as to where to buy one?

As already advised most of this information is within this thread but I will set it out for you.

Post1
I seem to be getting all the correct voltages to the mainboard. So I moved on to checking the U33 regulator that I've read about here.

This has established that U33 is a Voltage regulator.
............................................................................................

Post 10
See PlainBill explain what and how to test a voltage regulator at

https://www.badcaps.net/forum/showpos...1&postcount=23

This advises how to test a Voltage regulator
..................................................................................................
Post 15
Forgot to add that these are AMC1117 adjustable output regulators in the SOT-223 package

This advises the part number and the package (Shape of the component)
The important bit is just the 1117 AMC is the manufacturer you will see
later it is referred to as LM1117 which is the same part by another manufacturer
.....................................................................................................
Post30

Yes, U33 is an adjustable regulator. Notice the resistors located near the pads that adjust the output voltage. The part you're looking for is Digikey PN: LM1117MP-ADJCT-ND.

This advises where to buy and the part number. Go to Digikey.com
and cut and paste the part number into the serach box
..........................................................................................

Following from that there are tips on how to unsolder the device.

You can also get them on ebay- Just type in LM1117 but make sure to get "adjustable" Example:
http://www.ebay.com/sch/i.html?_trks...m1117&_sacat=0

If this does not fix your board then we can help a lot more if you please post good clear pictures of the whole chassis, and then pictures of each board, front and back and close up of connectors, (max resolution 2000x2000 and 2MB) using the manage attachments button, which is found by clicking "go advanced" under quick reply.

Please do not post inline and offsite as they slow down the loading of pages.

Examples of what is needed
https://www.badcaps.net/forum/attach...1&d=1290283049

https://www.badcaps.net/forum/attach...7&d=1280167246


There is no facility for making donations, if you want to support the site you can do so by purchasing capacitors from the http://www.badcaps.net site or by helping others with their queries.

The Forum Rules are here:
https://www.badcaps.net/forum/announcement.php?f=24

I hope this answers most of your queries and that you are able to save another set from the landfill.

[electronicsurplus]

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

Thank you very much for the help. I will order and try the regulator

very much appreciated

Jon

Hi electronicsurplus, Ok, you are currently working on a main board from a vizio GV42LFHDTV10A and you feel that the problem with it might be U33.

You are unsure how to test it or what it is and are unable to read the part numbers off it. (Sometimes they become clearer if rubbed with Isopropyl alcohol on a Qtip.)

Having established what it is, you want some guidance as to where to buy one?

As already advised most of this information is within this thread but I will set it out for you.

Post1
I seem to be getting all the correct voltages to the mainboard. So I moved on to checking the U33 regulator that I've read about here.

This has established that U33 is a Voltage regulator.
............................................................................................

Post 10
See PlainBill explain what and how to test a voltage regulator at

https://www.badcaps.net/forum/showpos...1&postcount=23

This advises how to test a Voltage regulator
..................................................................................................
Post 15
Forgot to add that these are AMC1117 adjustable output regulators in the SOT-223 package

This advises the part number and the package (Shape of the component)
The important bit is just the 1117 AMC is the manufacturer you will see
later it is referred to as LM1117 which is the same part by another manufacturer
.....................................................................................................
Post30

Yes, U33 is an adjustable regulator. Notice the resistors located near the pads that adjust the output voltage. The part you're looking for is Digikey PN: LM1117MP-ADJCT-ND.

This advises where to buy and the part number. Go to Digikey.com
and cut and paste the part number into the serach box
..........................................................................................

Following from that there are tips on how to unsolder the device.

You can also get them on ebay- Just type in LM1117 but make sure to get "adjustable" Example:
http://www.ebay.com/sch/i.html?_trks...m1117&_sacat=0

If this does not fix your board then we can help a lot more if you please post good clear pictures of the whole chassis, and then pictures of each board, front and back and close up of connectors, (max resolution 2000x2000 and 2MB) using the manage attachments button, which is found by clicking "go advanced" under quick reply.

Please do not post inline and offsite as they slow down the loading of pages.

Examples of what is needed
https://www.badcaps.net/forum/attach...1&d=1290283049

https://www.badcaps.net/forum/attach...7&d=1280167246


There is no facility for making donations, if you want to support the site you can do so by purchasing capacitors from the http://www.badcaps.net site or by helping others with their queries.

The Forum Rules are here:
https://www.badcaps.net/forum/announcement.php?f=24

I hope this answers most of your queries and that you are able to save another set from the landfill.

[electronicsurplus]

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

Hey guys,

Just wanted to thank you all and, to also add a helpful note, which makes this repair much faster.
I visited our electronic parts store which carries a small amount of transistors and capicitors. and, we cross referenced the regulator to the closest we could and ended up with a NTE956, which is much larger. I thought what the heck, why not try. I soldered it standing straight up since space up was not an issue and, used a leg from a resistor, kind of like a kickstand and, whamo, the set worked like a charm

So, the reason for this posting is that it is obvious that if you cannot find an exact replacement but, can find an electrically equivalent that it could work. it did for me. thanks a bunch guys

Jon
Electronic Surplus

[tom66]

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

Glad to hear you fixed your TV. Is it a regulator package like this? http://en.wikipedia.org/wiki/TO-220

If so I would recommend glue to hold it down as freestanding regulators can literally fall off the board if they are only held in place by solder.

[electronicsurplus]

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

You guys are the bomb

If there is ANYTHING I can do to repay please feel free to ask. I have 100's of parts televisions here which I hate to see go to the landfill. some have cracked or broken panels and/or scratches in the casings. I salvage the boards and, save them for future use of is some else needs one or so

Thanks again, I am psyched that I bfinally fixed a board. I am not afraid to say that I am not a professional technician. I do know a little bit but, it is limited to testing fuses and, some use of a multimeter. wish I knew how to test voltage regulators and mosfets, that would really help me a bunch

ASLO, I have a huge amount of pdf service manuals for a bunch of different sets. IF anyone needs a copu just ask and I can send no problem

Jon

[tom66]

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

If you have some service manuals, I am more than willing to host them on a http server for free. You can also upload them to Elektrotanya but the website in my opinion is badly designed and has too many restrictions.

[electronicsurplus]

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

Yes, it is exactly like that a TO-220 package. I am going to try silicone it to the adjoining caps to hold it steady. should work just fine

I also have some very good tips for Hitachi 50 Plasma, Philips/Samsung 42 Plasma, Polaroid and, some other televisions

if anyone needs please feel free to ask

Thanks again
Jon

[electronicsurplus]

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

Where can I upload them? There are about 100 or so

All factory service manuals and also training manuals which are even better. Some are NOT available anywhere which I obtained from a closed Factory servise center at auction

[tom66]

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

Where can I upload them? There are about 100 or so

All factory service manuals and also training manuals which are even better. Some are NOT available anywhere which I obtained from a closed Factory servise center at auction

Send me a PM and you can email them to me or use some service like dropbox. I'll host them on tgohome.com.

[budm]

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

Good job fixing it.
I also do volunteer works for WWW.CRC.ORG and we try to fix anything that can be fixed (using parts from others broken units for replacement parts) to keep them away from landfill.
I may contact you in the future if we do not have what we need.
Do you have website of the place?

[electronicsurplus]

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

Thank you VERY MUCH

Worked perfectly

you are the best

Any way I can ever help please ask

Jon
Electronic Surplus Recyclers LLC

Hi electronicsurplus, Ok, you are currently working on a main board from a vizio GV42LFHDTV10A and you feel that the problem with it might be U33.

You are unsure how to test it or what it is and are unable to read the part numbers off it. (Sometimes they become clearer if rubbed with Isopropyl alcohol on a Qtip.)

Having established what it is, you want some guidance as to where to buy one?

As already advised most of this information is within this thread but I will set it out for you.

Post1
I seem to be getting all the correct voltages to the mainboard. So I moved on to checking the U33 regulator that I've read about here.

This has established that U33 is a Voltage regulator.
............................................................................................

Post 10
See PlainBill explain what and how to test a voltage regulator at

https://www.badcaps.net/forum/showpos...1&postcount=23

This advises how to test a Voltage regulator
..................................................................................................
Post 15
Forgot to add that these are AMC1117 adjustable output regulators in the SOT-223 package

This advises the part number and the package (Shape of the component)
The important bit is just the 1117 AMC is the manufacturer you will see
later it is referred to as LM1117 which is the same part by another manufacturer
.....................................................................................................
Post30

Yes, U33 is an adjustable regulator. Notice the resistors located near the pads that adjust the output voltage. The part you're looking for is Digikey PN: LM1117MP-ADJCT-ND.

This advises where to buy and the part number. Go to Digikey.com
and cut and paste the part number into the serach box
..........................................................................................

Following from that there are tips on how to unsolder the device.

You can also get them on ebay- Just type in LM1117 but make sure to get "adjustable" Example:
http://www.ebay.com/sch/i.html?_trks...m1117&_sacat=0

If this does not fix your board then we can help a lot more if you please post good clear pictures of the whole chassis, and then pictures of each board, front and back and close up of connectors, (max resolution 2000x2000 and 2MB) using the manage attachments button, which is found by clicking "go advanced" under quick reply.

Please do not post inline and offsite as they slow down the loading of pages.

Examples of what is needed
https://www.badcaps.net/forum/attach...1&d=1290283049

https://www.badcaps.net/forum/attach...7&d=1280167246


There is no facility for making donations, if you want to support the site you can do so by purchasing capacitors from the http://www.badcaps.net site or by helping others with their queries.

The Forum Rules are here:
https://www.badcaps.net/forum/announcement.php?f=24

I hope this answers most of your queries and that you are able to save another set from the landfill.

[selldoor]

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

I was missing yesterday, but pleased to hear you got it fixed.

Thankyou for making the SMs available to us, could save lots of time for all of us
instead of trawling google hits.

Selldoor

[StingRay1971]

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

Hi Everyone!!! I seem to being having the same problem that people resolved on this thread in the past. I'll be grateful if you all can help me as well.

I tested everything and here are my results:

U2: pin 1: 2.05 , pin 2: 3.30, pin 3: 5.13
U7: pin 1: .023 , pin 2: 1.070, pin 3: 3.30
U8: pin 1: 2.05, pin 2: 3.30. pin 3: 5.16
U9: pin 1: .001, pin 2: 1.506, pin 3: 3.30
U33: pin 1: 2.05, pin 2: 3.30, pin 3: 5.13

I am not positive, but to me it looks like my issue is with U7 pin 2. How does the other readings work for my results?

What parts do i need to purchase from DigiKey, I searched results from past users but there are so many similar parts it was confusing for me. Any chance you can help me with a direct link to the product that needs to be purchased.

I know i need the Chip Quik Inc Kit and Aven Tool Tweezers.

Thanks for any help, be very appreciated.

StingRay

[budm]

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

"U7: pin 1: .023 , pin 2: 1.070, pin 3: 3.30" What is printed on this U7?
I believe it is supposed to be fixed 1.8V regulator, 1117-18.

[StingRay1971]

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

"U7: pin 1: .023 , pin 2: 1.070, pin 3: 3.30" What is printed on this U7?
I believe it is supposed to be fixed 1.8V regulator, 1117-18.

I see two lines of writing:

on top: AMC1117
below that: F03734F

I think on a preview post on page 2, someone said it should be 1.5.

In addition to my previous post, do you agree the U7 is only reading that looks off? I also thought U33 shared U7 and U9 so I thought all 3 would be out, but from the looks of it, i guess it is only U7?

Thx

[budm]

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

It does look low which I expect it to be adjsutable regulator, that is what we need to verify what the U7 really is, fixed 1.8V, 1.25V, 1.5V, or adjustable
See this thread: more likely to adjustable since there is other number following the 1117.
https://www.badcaps.net/forum/showth...ighlight=GV42L
https://www.badcaps.net/forum/showth...10A#post323846

[StingRay1971]

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

since there cheap I can't go wrong buying fixed and adjustable just in case.

I think its Regular 1.8V but not positive.