VIZIO V037L FHDTV20A powers up, backlight on, sound works, buttons work, no picture

[ivtec]

Re: VIZIO V037L FHDTV20A powers up, backlight on, sound works, buttons work, no pict

"my Vizio that i repaired had logo" Do you mean the VIZIO logo that is amber when TV is OFF and White when TV is ON but no backlights? If that is the case, then you did have backlights problem
The OP's TV has backlights, you can see Blue color on the screen, it the backlights are not on, the screen will be black.

i meant the tv came on regular but some times had just blue screen and acting crazy and sometimes working ok.

[triplefour]

Re: VIZIO V037L FHDTV20A powers up, backlight on, sound works, buttons work, no pict

ugh i totally messed up while i was testing the last regulator... my probe slipped and i think i touched pin1 to pin2 i had measured pin1 at 12v
and then i was going to measure pin2 and the probe slipped... i had the n64 still hooked up so i could hear the sound of mario kart. as soon as i made this mistake, the sound disapeared. i flipped up the tv and noticed the backlight was off. oh no i fried it! so i turned it off and back on again and the backlight came back on but the sound did not.
checking the regulators again i noticed that now i was getting all zeros on the one that was previously 12v... and of the other regulators i tested one of them was also 12v. all the rest are only 5v input. both of the regulators handling the 12v input are now reading 0 from all pins. all the other regulators still have the same readings. so basically i just lost 12v power to the motherboard. i checked the fuse by the power cable to the motherboard (or from it?) and it had no voltage. i unplugged everything and tested continuity, and yep the fuse is blown. the other fuze for the 5v is still fine.

please tell me all i did was blow a fuse, and that its easy to change?? ill upload a picture of the fuse. it doesnt look easy to change

i guess i should list all the voltages i found before i messed up. according to the math they all checked out good. and on the last one i guess i was expecting to read a 13.25 volt output but whoops!

ok here goes
U44 (this one reads all 0 now since the accident)
L061 G9117
1. 8.32
2. 9.57
3. 12.0

U15
1084 0851PL
1. 2.06
2. 3.3
3. 5.02
(i noticed this middle pin doesnt actually seem to be connected to the motherboard but both the pin and the trace on the motherboard read 3.3.. .whats that about? the other 0851PL is the same way)

U20
1084 0851PL
1. 0.55
2. 1.79
3. 3.27

U16 - AZ7805T (this one reads all 0 now since the accident)
1. 12
2. i dunno cause i blew the fuse right here
3. dangit!

[budm]

Re: VIZIO V037L FHDTV20A powers up, backlight on, sound works, buttons work, no pict

"U16 - AZ7805T (this one reads all 0 now since the accident)
1. 12
2. i dunno cause i blew the fuse right here
3. dangit!"

That is 5V regulator IC (78xx series), the middle pin is Ground, the left pin is Input, the right pin is Output. You probably blow the SMD fuse on the main board for the 12V input (This 12V is fed into this 5V regulator)

[johnboy1313]

Re: VIZIO V037L FHDTV20A powers up, backlight on, sound works, buttons work, no pict

There are small white fuses on the main board. I circled them in red on the attached pic. Check them for continuity.

[triplefour]

Re: VIZIO V037L FHDTV20A powers up, backlight on, sound works, buttons work, no pict

heres the fuses. the top one says Lf 5A and the bottom one says Lf 3A
the top one (5 amp) is blown and has no continuity.

please help!

[triplefour]

Re: VIZIO V037L FHDTV20A powers up, backlight on, sound works, buttons work, no pict

how hard are these fuses to get, and how hard to replace?

[triplefour]

Re: VIZIO V037L FHDTV20A powers up, backlight on, sound works, buttons work, no pict

theyre fuses so im thinking...easy and easier, right??

[budm]

Re: VIZIO V037L FHDTV20A powers up, backlight on, sound works, buttons work, no pict

I use axial lead fuse type such as PICOII fuse by Little fuse and just solder the new fuse to the old fuse's ends. Do you have any 5A or 4A fuse to use for testing for now?

[triplefour]

Re: VIZIO V037L FHDTV20A powers up, backlight on, sound works, buttons work, no pict

are the ceramic ones found in power supplies usually 5A? then yes...otherwise i cant think of any other fuses ive got laying around...

[triplefour]

Re: VIZIO V037L FHDTV20A powers up, backlight on, sound works, buttons work, no pict

ive got one here that says F5AL250V
i pulled it out of a dead PC power supply a few days ago.
does the 5A in there mean 5 amps?

[triplefour]

Re: VIZIO V037L FHDTV20A powers up, backlight on, sound works, buttons work, no pict

its actually not a ceramic one but it was not an easily removable one... so do i just solder wires to both ends and solder them to both ends of the blown fuse and call it good pretend it is?

[budm]

Re: VIZIO V037L FHDTV20A powers up, backlight on, sound works, buttons work, no pict

Yes, you can use it. Just solder small wires long enough to its end to allow you to solder the wires to the ends of the blown fuse, no need to remove the blown fuse, just tape up the fuse so you will not have another accident.

[triplefour]

Re: VIZIO V037L FHDTV20A powers up, backlight on, sound works, buttons work, no pict

something like this?

[triplefour]

Re: VIZIO V037L FHDTV20A powers up, backlight on, sound works, buttons work, no pict

oh yeah i gotta tape it for sure.

[triplefour]

Re: VIZIO V037L FHDTV20A powers up, backlight on, sound works, buttons work, no pict

ok just want to make sure this is what you meant before i go ahead and turn it on again...

[triplefour]

Re: VIZIO V037L FHDTV20A powers up, backlight on, sound works, buttons work, no pict

i burned some of the plastic on the clip for the power supply...but i think it will be ok... and im pretty sure im not touching anything else with the solder...

[budm]

Re: VIZIO V037L FHDTV20A powers up, backlight on, sound works, buttons work, no pict

That will do for now.

[triplefour]

Re: VIZIO V037L FHDTV20A powers up, backlight on, sound works, buttons work, no pict

nice ok ill get back with the results on that last regulator. thank u for being awesome!

[triplefour]

Re: VIZIO V037L FHDTV20A powers up, backlight on, sound works, buttons work, no pict

ok the fuse worked. both 12v regulators are back online. the one i didnt get to test earlier reads 12 on pin 1 , 0 on pin 2, and 5 on pin 3... thats how it should be, right?
i didnt get sound back yet but its because my n64 is messing up now! i need a more reliable a/v source for this test...

[triplefour]

Re: VIZIO V037L FHDTV20A powers up, backlight on, sound works, buttons work, no pict

ok awesome i got sound again still no picture tho... (but why would i? i havent fixed anything yet!)