Vizio regulator IC question

[danman]

I have a Vizio e320vl that does not turn on. When plugged in the vizio lights up amber but nothing happens when I hit the power button. I'm about 99% sure it is not the power supply because the voltages are correct. I don't get a reading on the 12 volt pins however so it leads me to believe that the main board is at fault. I don't have a digital voltmeter but when testing the regulators with my analog voltmeter the readings seem accurate except one regulator. When I try to test it the needle on my voltmeter doesn't budge. I'm assuming this is the regulator causing the problem. My question is what regulator is this? I've searched online to see what kind it is but I get no results. I edited a picture in the attachments to show you exactly what the regulator looks like. Any help would be much appreciated.

The first 2 1s could be ls but I'm not sure. It's really hard to see even though I have great eyesight its too faint to tell exactly what it is.

[budm]

Re: Vizio regulator IC question

1.8V fixed regulator.
Are you getting any DCV at the input pin of the regulator. Some of the regulator ICs on the board may not have any input Voltage until the 12VDC is present.
The 12VDC power supply is turned on by the PS-ON signal generated by the main board when power switch is activated.
You should post TV questions in the TV section.

[danman]

Re: Vizio regulator IC question

turns out I was way off. I didn't know my phone was capable of this kind of picture but I got an excellent shot of the chip, so here it is.

[danman]

Re: Vizio regulator IC question

1.8V fixed regulator.
Are you getting any DCV at the input pin of the regulator. Some of the regulator ICs on the board may not have any input Voltage until the 12VDC is present.
The 12VDC power supply is turned on by the PS-ON signal generated by the main board when power switch is activated.
You should post TV questions in the TV section.

Sorry about that. I'm new here. If someone wants to move this thread feel free. I'm not getting a reading on any of the pins on that chip. The other regulators have readings that seem normal but as I said I don't have a digital voltmeter right now so I can't say for sure.

[budm]

Re: Vizio regulator IC question

You have to find out at least if you do have input Voltage, no input Voltage = No output Voltage.
So look up the spec sheet to get the pinout of the IC and go from there.
You should also read this:
https://www.badcaps.net/forum/showth...999#post300999

[danman]

Re: Vizio regulator IC question

You have to find out at least if you do have input Voltage, no input Voltage = No output Voltage.
So look up the spec sheet to get the pinout of the IC and go from there.
You should also read this:
https://www.badcaps.net/forum/showth...999#post300999

Input voltage; that's the pin on the right correct? If so I checked it and got no reading. Would that indicate that the chip is bad? All the other regulators have readings on the input pins. If it is that the chip just isn't getting power because the power supply isn't on where do I go from there?

[danman]

Re: Vizio regulator IC question

Also I'm new to testing regulators and all that. I've done low level surface mounts in the past on ICs but I don't know how I would go about finding the pinout of the IC in question.

[Agent24]

Re: Vizio regulator IC question

Also I'm new to testing regulators and all that. I've done low level surface mounts in the past on ICs but I don't know how I would go about finding the pinout of the IC in question.

The same way you find out the pinout for any IC.

Find out the IC part number and look up the datasheet. The datasheet should have a picture showing the pins and their names\functions etc.

In this case it may not be obvious, but as already mentioned what you have is a generic 1117 type regulator IC. It's a low-dropout linear regulator and they are very common in many products. They come in many options with various output voltages and also adjustable versions too. Like any very common IC, they are made by many many companies, but are all ultimately the same, including the pinout. So, find yourself the datasheet for a 1117 regulator and look at it

In your case it's a 1.8v regulator - that's what the "18" on the package means.

Alternatively to the datasheet, the board designers have very nicely silk-screened the pinout on the board next to it as well! (NOTE: Sometimes silk-screens can be wrong! In this case it is correct, but bear that in mind!)

Refer to the link budm already posted to see how to actually check the regulator...

[danman]

Re: Vizio regulator IC question

The same way you find out the pinout for any IC.

Find out the IC part number and look up the datasheet. The datasheet should have a picture showing the pins and their names\functions etc.

In this case it may not be obvious, but as already mentioned what you have is a generic 1117 type regulator IC. It's a low-dropout linear regulator and they are very common in many products. They come in many options with various output voltages and also adjustable versions too. Like any very common IC, they are made by many many companies, but are all ultimately the same, including the pinout. So, find yourself the datasheet for a 1117 regulator and look at it

In your case it's a 1.8v regulator - that's what the "18" on the package means.

Alternatively to the datasheet, the board designers have very nicely silk-screened the pinout on the board next to it as well! (NOTE: Sometimes silk-screens can be wrong! In this case it is correct, but bear that in mind!)

Refer to the link budm already posted to see how to actually check the regulator...

Thank you guys for your help. Either way I'm not getting any kind of reading on this chip so either it doesn't get a load until the power supply has been turned on or the chip is no good. What would be my next step in diagnosing the problem with this tv?

[budm]

Re: Vizio regulator IC question

No input Voltage = No output Voltage.
The next thing we need will be be the good clear pictures of the whole back side of the TV so we can see how all the boards are connected, and the good clear pictures of the power supply board so we can see all the pin labels of all the connectors.
Then we will need the DCV readings of all the connectors when TV is plugged in and when power switch is activated, you MUST provide all the pin names next to each readings.

[mariushm]

Re: Vizio regulator IC question

It's probably a 1117 1.8v linear regulator, but don't take my word for it. Most likely SOT223, but could be SOT89 ...

See for example : http://www.digikey.com/product-searc...=0&pageSize=25

Something that may be the right part: http://www.digikey.com/product-detai...ICT-ND/4505204

Read the datasheet linked on the page.

[danman]

Re: Vizio regulator IC question

In order from left to right I'm getting roughly 5.6v on the first three pins then 0 after that. When I try to turn on the TV I get nothing on the 12 volt pins.

[budm]

Re: Vizio regulator IC question

"Then we will need the DCV readings of all the connectors when TV is plugged in and when power switch is activated, you MUST provide all the pin names next to each readings."
So try again. Without the names how we tell what are missing?

[Agent24]

Re: Vizio regulator IC question

From the silkscreen it looks like from the left, the first 3 are 5.2v standby, next 4 are GND, the next 3 are 12v, although the colours are inconsistent - looks like they just used rainbow cable! We need to see the bottom of the board to see if the pins are actually connected together or if the silkscreen is just wrong.

Last 4 pins with thinner wires are probably the control lines instead of power, last one is DIM anyway... Are there any names silkscreened to say what those pins do? Might be they tell you on the other end of the cable at the mainboard??

Looks like:

Pin 1 - 5.2vSB
Pin 2 - 5.2vSB
Pin 3 - 5.2vSB
Pin 4 - GND
Pin 5 - GND
Pin 6 - GND
Pin 7 - GND
Pin 8 - 12v
Pin 9 - 12v
Pin 10 -12v
Pin 11 - ??
Pin 12 - ??
Pin 13 - ??
Pin 14 - DIM

[budm]

Re: Vizio regulator IC question

The picture that I marked, there are pin names to the right of the connector.

[danman]

Re: Vizio regulator IC question

The picture that I marked, there are pin names to the right of the connector.

Sorry about that. I'm a newb. Here's a pic with the names.
The colours of the wires from left to right are

Black
Brown
Red
Orange
Yellow
Green
Blue
Purple
Grey
White
Black
Brown
Red
Orange

Not sure if that helps about the colours.

[danman]

Re: Vizio regulator IC question

Again the readings don't change when I hit power. The main board isn't turning on the ps.

[Agent24]

Re: Vizio regulator IC question

The colours don't really matter, I only mentioned it because *usually* the wires which carry the same power rail are the same colour, but they are obviously just cost-cutting here...

So there is no PSON signal at Pin 11? (The white wire)

[danman]

Re: Vizio regulator IC question

Pin 11 is the small black wire, but I checked the white one(pin 10) anyway and pin 11 and when i hit the power button the voltmeter doesn't read anything on either of them. I'm about 90% sure it's a problem with the main board.

[Agent24]

Re: Vizio regulator IC question

Sorry! I meant to write "The thin black wire next to the white wire"

Anyway, if you got no voltage at Pin 11 \ PSON signal then that is a problem. It should be at least a couple of volts to tell the PSU to come up out of standby and into full power mode.

Sounds like the mainboard may not be sending the PSON signal.