Vizio 40” V405-H19 has backlight, no display

[nomoresonys]

Re: Vizio 40” V405-H19 has backlight, no display

might have gotten a bad mainboard from sj, maybe send it back and have them send you another.

[triplefour]

Re: Vizio 40” V405-H19 has backlight, no display

Good lord. Here I was complaining about tcons being built into main boards but this guy's got a tcon built into the panel board! Vizio is one step ahead in the cost cutting / making it hard to fix game

[triplefour]

Re: Vizio 40” V405-H19 has backlight, no display

might have gotten a bad mainboard from sj, maybe send it back and have them send you another.

But if the vgh and vhl are wrong, isn't that something only related to the tcon? Genuinely asking cause I don't know where those voltages are generated.

[dskall]

Re: Vizio 40” V405-H19 has backlight, no display

VGH and VGL are generated on t-con.

[triplefour]

Re: Vizio 40” V405-H19 has backlight, no display

VGH and VGL are generated on t-con.

Thanks. Thats what I suspected. So in this case it couldn't be a main board problem making those vgh and vgl wrong?

[dskall]

Re: Vizio 40” V405-H19 has backlight, no display

As far as voltages the main only supplies 12v. Required panel voltages are generated by t-con

[triplefour]

Re: Vizio 40” V405-H19 has backlight, no display

As far as voltages the main only supplies 12v. Required panel voltages are generated by t-con

The main board has to give the tcon some other small voltage signals for the picture data...most of the pins on the connector going to the tcon are those, right? And a few are for the 12v. I guess I should try lookup a pinout to see for sure what the mb sends.

Also while they're busy integrating boards that they shouldnt be, who's to say they haven't put half of the "tcon" on the mainboard and the other half on the panel boards??

[dskall]

Re: Vizio 40” V405-H19 has backlight, no display

The main supplies 12v, data signals and some other information. The t-con generates the required panel voltages and timing signals to run the panel. The chip around your vgh and vgl test point is probably the one generating those voltages. So you either have a short or bad ic.

[nomoresonys]

Re: Vizio 40” V405-H19 has backlight, no display

ok, if tcon is on the panel not mainboard, might be the dc to dc converter ic.

[mattd1979]

Re: Vizio 40” V405-H19 has backlight, no display

Wow, that was a lot of information and good Q/A. Is there a way to test the IC? I suppose I would need a pin out diagram and what the voltages should be.

[dskall]

Re: Vizio 40” V405-H19 has backlight, no display

You could check those test points for shorts. You could cut the traces and check the voltage. Check the caps around the ic. Check for 12v to the ic.

[nomoresonys]

Re: Vizio 40” V405-H19 has backlight, no display

I don't know exactly how they work either but I think you want to look for 12v going in and 3.3v coming out on one of the pins.

[mattd1979]

Re: Vizio 40” V405-H19 has backlight, no display

Which of the 3 ICs do I check?

[dskall]

Re: Vizio 40” V405-H19 has backlight, no display

Looks like right one.

[diif]

Re: Vizio 40” V405-H19 has backlight, no display

There will be different voltages on each on the coils, so it's the middle and right but identify the markings to be sure.

[mattd1979]

Re: Vizio 40” V405-H19 has backlight, no display



The only two voltages I found close to what you were asking was pin 1 starting from the top left above the “I” in “INX” which measured at 4.970V and pin 3 above the “N” at 12.63V. I tried looking up the chip but couldn't find anything specific.

[mattd1979]

Re: Vizio 40” V405-H19 has backlight, no display



I included the above drawing. Hopefully you can make sense of my scribble.

I still need to draw a diagram of the other chip but I measured 12.63 volts as well as 5v. There were other voltages that measured between .600 and 1.5 volts.

[nomoresonys]

Re: Vizio 40” V405-H19 has backlight, no display

I can't seem to find a datasheet on it either.

[triplefour]

Re: Vizio 40” V405-H19 has backlight, no display

Nice...tcon integrated into panel boards and secret ICs... they really don't want you to fix these

If that ic is bad and there's no way to buy a new one then your only chance would be to take it from another TV but most ebay sellers don't tear off and sell the panel boards. Now that the tcon chips are there, maybe they should. I've been saving all my panel boards even tho they don't have tcon on them.