vx37l no picture no sound

[eagle00799]

Re: vx37l no picture no sound

well i wish i could check these fuses but my cheapo meter does not have 200 or 2000 ohms. but i i do get continuity.

[selldoor]

Re: vx37l no picture no sound

Unfortunately continuity is not enough- is it analogue? post a pic of your meter - phone pic will do.
If you want to continue a meter that gives ohms in 3 figs is essential. I think you can get a cheap multimeter for around 5$ is the US?

[tom66]

Re: vx37l no picture no sound

Continuity could be fine if the meter also displays a reading while doing this.

[cashkennedy]

Re: vx37l no picture no sound

torch = flashlight , incase anyone doesnt speak british
they have $5 multimeters at harbor freight tools in america.
But i bet your mulitmeter goes to 200 ohm from the same setting as continuity.

Although it doesnt hurt to check, I would expect a backlight issue to either do 2 seconds to black, or have sound come on. And if it did have sound come on, it would be "missing" the error , and not require the plug to be pulled to shut it off.

I believe haveing to shut off by pulling the plug always indicates on vizios that the motherboard is not creating / or receiving stable power to even reach an error state / or start.

I see what your getting at selldoor with the wires being out of order, but they have spots on each connector / socket for the 2 extra wires, probably have the pins on each socket wired identically, so that you can connect the inverters in either order. But might be worth a try to investigate that. But if the TV has always been owned by eagle and used to work, then it broke before anyone could have changed the order of the wiring, and so thats not the original/main problem.

[selldoor]

Re: vx37l no picture no sound

@cashkennedy
I see what your getting at selldoor with the wires being out of order, but they have spots on each connector / socket for the 2 extra wires, probably have the pins on each socket wired identically, so that you can connect the inverters in either order. But might be worth a try to investigate that. But if the TV has always been owned by eagle and used to work, then it broke before anyone could have changed the order of the wiring, and so thats not the original/main problem.

OP originally asked
Also the 2 24v rails are the same but the plugs are different, 1 has 10 wires with the A and B empty and the other plug all 12 holes are occupied with 2 white wires going to the B pin. I might have gotten these 2 plugs mixed up and now am not sure which plug goes to which rail. Again any help would be greatly appreciated.

I am quite happy with where I have said the plugs should go.
So with respect, you can investigate it if you want to

[cashkennedy]

Re: vx37l no picture no sound

Ah okay, i missed where he asked about the wires. Didnt see where you recommended an orientation either. But im sure you got it right based on your picture of another unit. Though i still wouldnt be surprised if they are interchangeable. And of course his original problem is unrelated then, but i didnt know that was already clear

[budm]

Re: vx37l no picture no sound

I just look at the power supply board. FYI: the two connectors (12-pin) are connected in parallel (1 to 1, 2 to 2, so on) so either one of the female connectors can be installed without any problem (the one with 12 pins is for the Master Inverter board because it needs the A (analog dimming control), and B is for the BL_ON control. These A and B pins are also connected to the 13-pin connector labeled with A, and B which goes to the main board.

[eagle00799]

Re: vx37l no picture no sound

well it turns out that my meter does have a automatic ohm feature so there's no turning it from 200 ohms to 2000 ohms, it does that by itself automatically. I checked the fuses on the inverter board and I get 0 readings. And the transformers are as follows and remember I am doing this from my phone so I will t ry to have this in order like selldoors example so bare with me.[LIST=1]
t1- 4-5 2.25k
1-8 2.19k
T2 4-5 2.26
1-8 2.24
T3. 4-5 2.28
1-8 2.25
T4 4-5 2.23
1-8 2.24
T5 4-5 2.26
1-8 2.23
T6 4-5 2.27
1-8 2.26
T7 4-5 2.26
1-8 2.24
T8 4-5 2.26
1-8 2.28
I will now put it together so I can check with a light and a dvd player to see if there's anything on the display at all. And how do we tell if its putting out enough power to reach the error state like budm was saying?

[eagle00799]

Re: vx37l no picture no sound

Sorry, that was cashkennedy that was talking about the power issue and not budm.

[eagle00799]

Re: vx37l no picture no sound

There is no flicker/flash on the screen and no sign of a display from the Dvd or antenna.

[selldoor]

Re: vx37l no picture no sound

OK That is great from phone - tables are bad to format even from a pc.
They look ok - Just to tell you what you were testing them for. The results from each
transformer should be within 3% and all the transformers should be within 3% of each other and obviously with no shorted or open ones. If the transformers are not within 3% a protection circuit closes them all down. So no back light ( but it usually flashes on for 2 seconds) I asked you to do the test now only because the set was in bits - normally you find out if it flashes first then do the test when it is apart.

Just so that you know you can normally edit a post for 30 mins to an hour
(perhaps not from a phone)
so you may have been able to change Bm to Ck Only use it sparingly and dont change anything really important especially if someone has posted since.


So no flash and no pic - will have to think some more.

[eagle00799]

Re: vx37l no picture no sound

Here is an update, I ran into a buddy that had a 42" vizio with a broken screen that was willing to let me use his control board to see if I could get any display (all the plugs were the same size so it plugged right in) The power supply and inverters had different plug ons so they wouldn't work but anyway I got the blue screen with the no signal so I hooked up the Dvd thru the hdmi and the movie and sound came on but the picture was displayed in the wrong size and off center so I assume that's because the board is for a 42". So this brings me back to the high readings I got from U7-3.29,1.11,23.8 that's clockwise . Anyone's thoughts on this?

[tibimakai]

Re: vx37l no picture no sound

on that board should be a 5V and 12V only, no? From where is coming that 23.V?
U7 and U9 it's supplied by U33 if I know well.
I'm working on the same model TV, just with different issue.
I would replace the U7, just to make sure that it's not a bad one.

[budm]

Re: vx37l no picture no sound

Can we see the pictures of this U7?

[eagle00799]

Re: vx37l no picture no sound

U7 is identical to U2,4,8 and 33 and all these are Amc1117 F0734F, when I set my meter on 10 megohm input DCV I get an "auto" in the little display of the meter, I get 3.29V,1.11V,23.8MV is this millavolt or megavolt? It was my mistake reading it before,I didn't notice the "V" changing to "MV" so U7 is probably ok?

[budm]

Re: vx37l no picture no sound

Now that make more sense, to have 23.8Vdc feeding that IC will be bad news, so it is basicaly 0V, or 0.0238Vdc. Does one of the pin has two resistors connected it? That is why I want to see the pictures. If I am correct, I owuld expect to see 1.25V at the output pin, the input is about 3.3V which looks correct.

[tibimakai]

Re: vx37l no picture no sound

I had a breakthrough with mine, though not sure what I did that "fixed" it to a point.
I guess I have tried using budm's suggestion to use the min/max on my meter, but course I didn't know what I was doing because it was maxing out with OL, but after this the TV stayed on with white logo.
I have checked the inverter transformers and found different values then you.
My primaries were 1.6xxKOHM and the secondaries were 6.1KOHM except T1's which was 158KOHM.
So I guess this is my problem.
Now where can I find this transformer?
I will douple post this in my thread also.

[cashkennedy]

Re: vx37l no picture no sound

Well since a different mainboard fixed eagle's problems we know that is where the problem is, and that its not from the inverters.

U7 works differently in this set then in the 32" ones, they renumber all the IC's in each model...

Budm is right that in these vizios they just connect the adjust/ground pin to 2 resistors 1 leads to ground, the other to the ouput i believe. If you look closely at the board you can see that, and then test the resistance between the adjust/ground pin and the other ends of the resistor.

My 32" vizio had intermitent problems with one of these 1117 regulators, so i actually think they are overheating on these boards, and then either failing or destroying the adjacent traces/joints. You could try fixing yours by just soldering new wires to circumvent all the traces on the boards (what i finally did), but i would sugest replacing U7 before doing that.

[eagle00799]

Re: vx37l no picture no sound

I am going to to order another board. I am not skilled enough to replace anything on the circuit board myself an d the local repairman says he isnt into LCD TV's much.(He is semi retired and does very little anymore and another repairman in a neihboring town says replace the board cause they dont make parts to replace just the components of the board. After i recieve the other board i will fiddle with this one some more, would be nice to know axactly what the problem is and where are you all getting your parts/ i know someone has to be making parts that will work.

[cashkennedy]

Re: vx37l no picture no sound

There are quite a few places you can get the parts from, the person who said that either is dumb, or says that to save time explaining that he doesnt feel it's worth his time to go about repairing problems on the component level.

digikey.com and mouser.com both stock 1117 regulators, its a fairly standard part that many brands make. Even the rarrer items are usually available from either of those sites though

Replacing a regulator (or a surface mount 3 pin transistor to be more general), is neither hard nor easy, but requires a proper soldering iron for electronics work. If you want to go that route, we can deffinetly approve which 1117 regulator you choose to use before you buy it, and give you tips on how to replace it. The part itself is under 1 dollars, but shipping will add another 5-7 dollars. Buying a soldering iron will be 15-60 depending on the quality you want.