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

[triplefour]

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

again why cant we find a diagram for this board? it should be a crime not to make these schematics freely availiable

[budm]

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

OK, just do more resistance probing.

[triplefour]

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

maybe it is out there somewhere...but i just cant google good enough :'(

[triplefour]

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

ok which resistances should i check now? can i forget about the mx12g?
should i put one probe on j30 and just go crazy probing everything in sight and then write down all the values and label them on the picture?

[budm]

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

I wonder what the repair kit is?
http://www.ebay.com.au/itm/VIZIO-Mai...-/131030297620

[budm]

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

ok which resistances should i check now? can i forget about the mx12g?
should i put one probe on j30 and just go crazy probing everything in sight and then write down all the values and label them on the picture?

That's about the only way.

[budm]

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

Well here is the stupid Vizio service manual, NO DIAGRAM!

[triplefour]

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

yeah i was complaining about that earlier. i looked at it and found it completely worthless

[triplefour]

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

ok well it took a lot of time but i made pretty much all the measurements i could stand. writing them down on the picture now. gimme a minute.

[triplefour]

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

i measured some resistances lower down on the board than whats shown in this picture. ill have to take another picture to show it.
but heres what i got so far.

[triplefour]

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

heres the other part

[budm]

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

OK, on post 86 you said you read 0.03 Ohms on two pads of MX-12g, now you showing the reading of 1506 ans also show 889 for the pad of c858 wwich is connected directly to those two pad of MX-12G, that cnnot be right.
But no matter what, that IC is NOT the MOSFET we are looking for, do not waste any more time testing that IC. You need to probe other components.
Your Ohm readings are not consistence as you can see you are reading the same connection but comes up with different readings.

[triplefour]

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

ok in post 86 i think there was some miscommunication. now that im re-reading it. you wanted me to put one probe on j30 and test those points. but i was testing between pin1 of the mx-12g and the other 2 points circled. thats when i got the .03 resistances.

later when i tested everything from the j30 i went over and over double checking to make sure. so those are assuredly the resistances from j30.

sorry for the confusion.

did i still not probe enough stuff? what else should i try? what am i looking for? to find something going from j30 that has .03 resistance?

[triplefour]

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

idk how but i think i just didnt see the post u made directly before me on that one...im gonna test resistance between j30 and any mosfet type looking things. looking for low resistance...

[triplefour]

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

ok so with the black probe on j30 i ran the red probe all over the place...i dont think i tested every mosfet on the board but every one in that area for sure. and i only found this one that has .4 ohms resistance on 4 legs

i circled it in the picture.
4853GM
908034

or is it
4B53GM
908031

?

so is this the MOSFET we're looking for, obi?

[triplefour]

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

oh yeah im also wondering (and should have asked earlier) how you know that j30 is supposed to be 12v when we dont have a schematic? is that just how most vizios are?

[budm]

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

OK that may be it! Take the DCV reading on the 4 pin on the right, the two pin (pin 1 and pin 3, you can see that they are connected to positive pin of cap CE64 ) should have 12VDC.
Give me the reading of all 4 pins on the right (pin 1 ~4).
"oh yeah im also wondering (and should have asked earlier) how you know that j30 is supposed to be 12v when we dont have a schematic? is that just how most vizios are?" Just from experience, other TV may not used other pins, when you work on many units as I have, you will kind of know which pin will be for the b+.
P/N is AP4853GM

[triplefour]

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

ok ill go take those measurements now. what do u mean by b+ ?

[triplefour]

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

its for the pins on the right from top to bottom 11.95 , 12.05, 11.95, 12.05 ...

[budm]

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

Just to be sure, the 4 pin (all tied together on the pad) on the left has 0v or near 0V?