Vizio regulator IC question

[danman]

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.

Do you know how I could go about testing the mainboard to see what component is failing? Again I appreciate all your help.

[danman]

Re: Vizio regulator IC question

vizio doesnt have a schematic diagram of this main board otherwise i would try my best to diagnose it myself but I have little knowledge on this stuff so I need a pro to help me out.

[Agent24]

Re: Vizio regulator IC question

Lack of schematic is always a problem with these things... makes it hard to do...

There are 2 things I can think of doing right now.

1) Make sure the PSU is OK. To do that you would need to manually jumper it on. Disconnect the output cable from the mainboard (important!), and then use a 1k ohm resistor to jumper 5.6vSB to PSON.
That should bring up the 12v output. If that works we know it's the mainboard at fault here.

2) Start looking at the mainboard for ideas... post good clear photos of it here. We need to find any fuses that may be on it, and start checking those for a start. Also that regulator you started with may provide some clues. We need to find out of it is powered from the 12v rail or somewhere else.

EDIT: also it's possible your EEPROM is bad. This is a known problem and the set not coming out of standby is one symptom of that. You can get new EEPROMs online, but it would pay to check the more basic stuff first.

[danman]

Re: Vizio regulator IC question

Can't I use a paperclip to jump the psu

[Agent24]

Re: Vizio regulator IC question

Can't I use a paperclip to jump the psu

IF the PSU already has a resistor to limit current in that part of the circuit, then maybe.. but since we don't know, you should use a resistor as it's safer. Otherwise you risk destroying something and then you make the problem even worse.

[danman]

Re: Vizio regulator IC question

OK I'll see if I have any but I doubt it. I have another vizio but different model so I tried putting that PSU in to see if it would work but the same problem. I know that PSU works because the other visio turns on. It has a different issue I'll probably post in another thread after I figure out what's wrong with this one.

Anyway here's a picture of the main board with the regulator in question circled.

[Agent24]

Re: Vizio regulator IC question

Well first thing would be to check the fuses on the mainboard right next to the power input. Check parts F1 and F2 there for continuity.

[danman]

Re: Vizio regulator IC question

Okay I tested F1 and F2 and they were fine. I decided to test some other fuses and I got no continuity on the one in this picture.

[budm]

Re: Vizio regulator IC question

Does it have 'F?' designator printed next to it? It does not look like fuse to me.

[danman]

Re: Vizio regulator IC question

Oh no it doesn't. It says tc90. The one to the bottom right that looks exactly the same has continuity so I just assumed.

[Agent24]

Re: Vizio regulator IC question

Those are surface mount ceramic capacitors, not fuses.

I found a good photo from SJ, only those 2 fuses next to the power connector are what i can see.

[danman]

Re: Vizio regulator IC question

Those are surface mount ceramic capacitors, not fuses.

I found a good photo from SJ, only those 2 fuses next to the power connector are what i can see.

Okay and they were fine. Where do I go from here?

[budm]

Re: Vizio regulator IC question

SJ sells EEPROM if you have problems as shown below:
http://www.shopjimmy.com/catalogsear...q=Vizio+e320vl

IMPORTANT:
These main boards can have multiple failures, in addition to the EEPROM.
If EEPROM replacement does not repair your board, there are likely additional problems.
From SJ:
Symptoms EEPROM replacement CAN fix:
- Display is frozen on VIZIO logo screen*
- TV won't power on with remote/buttons when plugged-in (VIZIO is lit in orange, but won't turn to white)
- TV turns on when first plugged-in, but it won't turn back on after 30 minutes of being off
- TV shuts off and goes back to standby mode (orange VIZIO lit) after you turn it on

Symptoms EEPROM replacement CAN NOT Fix:
- TV turns on but has NO backlight
- TV turns on AND backlights are on, but has no video display at all
- HDMI issues
- Audio issues

And BTW, those 2 fuses on the main board are for the 5VSTBY and for the switched 12V.

[danman]

Re: Vizio regulator IC question

Is there anyway to test the EEPROM? I guess that's what my first question should have been. I've done a ton of research on these piece of **** tvs and EEPROM is a big one. Every I know who has had a Vizio has had problems. People need to get the word out on how crappy these tvs are.

[Agent24]

Re: Vizio regulator IC question

I think the only way to (somewhat) test an EEPROM is to read it and compare with a known good copy of the data.

Since I'm assuming you probably don't have the equipment to do that, or a known good copy of the file, the easiest solution may be to just replace it with a new one.

At this point you could also check all the voltage regulators that run from the 5.6v standby rail (finding which ones these are would be fun without a schematic) and ensure they are working.

Since your model has a known EEPROM problem and your fault symptom is consistent with a bad EEPROM, it may be worth trying that.

[danman]

Re: Vizio regulator IC question

I think the only way to (somewhat) test an EEPROM is to read it and compare with a known good copy of the data.

Since I'm assuming you probably don't have the equipment to do that, or a known good copy of the file, the easiest solution may be to just replace it with a new one.

At this point you could also check all the voltage regulators that run from the 5.6v standby rail (finding which ones these are would be fun without a schematic) and ensure they are working.

Since your model has a known EEPROM problem and your fault symptom is consistent with a bad EEPROM, it may be worth trying that.

For sure. Thank you guys for all your help. I'll get back to you after I replace the EEPROM. Might be a while though.

[danman]

Re: Vizio regulator IC question

1 more question. Do you know if any of those pins can be bridged on the EEPROM? I just have a soldering gun and it's easier if I can bridge some of the pins. The last IC I soldered had pins that were able to bridge and made it much easier then soldering each individual pin.

[Agent24]

Re: Vizio regulator IC question

1 more question. Do you know if any of those pins can be bridged on the EEPROM? I just have a soldering gun and it's easier if I can bridge some of the pins. The last IC I soldered had pins that were able to bridge and made it much easier then soldering each individual pin.

I doubt it. I have never seen a serial EEPROM that had any NC or duplicate pins. Nor a parallel one that did for that matter.

With a lot of extra flux and a careful application of the soldering gun you might be able to pull it off, BUT I would not recommend a soldering gun on such a delicate multilayer board anyway.

I would strongly advise you get a 25-30 watt pencil iron with a medium-small chisel tip and use that. Even a cheap one should do. With care, you can solder individual pins at a time, although you may find it easier to use a drag soldering or flood-and-suck method. You can find videos for these things on YouTube.

But in any case, with SMD parts, lots of flux and very little solder is key to avoid bridges when soldering by hand.

[danman]

Re: Vizio regulator IC question

Okay I got the EEPROM. The guy also suggested replacing the memory capacitors to prevent the problem from happening again. In the picture am I correct on the EEPROM chip and the memory capacitors? The capacitors that are on the board are larger than the ones I ordered.

[Agent24]

Re: Vizio regulator IC question

I think you are correct on the EEPROM (check IC part number to be sure)

No idea about the capacitors. If he suggested it, you should probably ask him which ones he's talking about. Did he send you those new capacitors too?