Vizio/LG E420VT

[TechShui]

It's a Vizio with LG parts. PSU seems to be a common fault since ShopJimmy is selling repair kits. I opened it up and found C604A toasted there's also a burn mark above R275 just below where it says LGIT E-series 42.

A little burnt near Diode mosfet D603 but perhaps that's from the same cap explosion because when I test the diode it reads fine. 443 one way and infinity the other direction.

One thing that bothers me is I'm getting almost no reading off the two resistors below the blown cap, R603/R604.

About .4 ohm at lowest setting on multimeter but the new resistor in the repair kit reads the same. Colors are Brown, black, silver gold and black so that's 10ohm with 20% tolerance right?

I also read this thread https://www.badcaps.net/forum/showthread.php?t=26439

And budm mentions the resistor shorting so that's why I'm particularly worried about them but are they actually just like .8 or something? Are these resistors fine?

I will post pictures of the parts in the repair kit too. They sent me like three different ICs and even SMD resistors and zener diode. For what location I have no clue because they are marked with wrong designation. C604A is marked C9307.

Top of board:
https://www.instagram.com/toppuramen...=1wuukgc7uzpp6

Bottom:
https://www.instagram.com/toppuramen...=1xf9nd82l1r00

Repair kit:
https://www.instagram.com/toppuramen...d=m72zee73q357

[budm]

Re: Vizio/LG E420VT

http://www.camradio.net/resistors.html
Colors are Brown, black, silver gold = 0.1 Ohm. You have to subtract your meter probes resistance from the reading.
Please up load hi res pictures here so I can zoom in and see the component better.

[TechShui]

Re: Vizio/LG E420VT

Which component do you want to see? The resistor in question, right? I can zoom in on that but unfortunately my camera is not the best so I tried many times to get a full picture of the board but it still is a little fuzzy to read the designators (R275, etc) at that resolution.

[TechShui]

Re: Vizio/LG E420VT

So does anyone have the service manual? I replaced C604A and now get a flickering backlight and loud buzzing from the transformers. Should I start looking at PFC or what next?

Diodes near the cap all seem okay
D601 and D601A are 596 one way and infinite other.
D603 (the diode mosfet under the heat sink) is 496 and infinity other way.

[R_J]

Re: Vizio/LG E420VT

start by checking the voltage across one of the main filters (68µf/450v) in standby it should be about 160 volts, when the tv is turned on it should be close to 400v
R603/R604 are low Ω resistors, and they read like a short, which is good, if they were open then the fets would have been shorted.

[TechShui]

Re: Vizio/LG E420VT

Speaking of standby mode, the TV comes on as soon as I plugged it in. So it never really has standby. I'm guessing something is sending the PWR_ON signal even when it shouldn't.

Want to try to avoid buying a new power board since they are pricey and hard to find but this feels pretty lost in the dark until I get a service manual for it.

[budm]

Re: Vizio/LG E420VT

If the PWR-ON is present then all you will care right now if the PFC Boosted Voltage is present or not. So you need to look at the PFC section if you do not have Boosted Voltage with present of PWR-ON signal.
Most TV will remember last state, if the TV was on and you remove the power cord, then when you plug the power cord back in the TV will be in the power on mode.

[TechShui]

Re: Vizio/LG E420VT

What do you want me to prove for the PFC boosted voltage? Is that one of the pins IC150?

Or is it on the underside of the power board?

And I still have no luck finding a service manual. What’s the best site for them? Is allservice.ro dead now?

[budm]

Re: Vizio/LG E420VT

Is this your exact board?
https://www.shopjimmy.com/vizio-080g...led-board.htm#
SMD IC601 should be the PFC controller IC, get the P/N to get the spec sheet then check to see if it has VCC for it to run or not.

[TechShui]

Re: Vizio/LG E420VT

Is this your exact board?
https://www.shopjimmy.com/vizio-080g...led-board.htm#
SMD IC601 should be the PFC controller IC, get the P/N to get the spec sheet then check to see if it has VCC for it to run or not.

Yes that's my board. I ordered the board repair kit off ShopJimmy. But the designators are different I explained that in my Opening Post. This board does fit several TVs such as Insignia and LG but shouldn't the designators be the same?

Maybe they sent the wrong kit. But some of he components are the same like there is a PFC controller which I will probably replace. But instead of an Infineon HS01G it's a LD7591 (with designator IC9801 instead of IC601).

I tested the original PFC booster IC and it's got 15v at VCC.
Here are the full readings:

HS01G

1. (FMIN) 0.0v.
2. (CS) 5.0v
3. (Feedback voltage) 0.0v
4. (VINS) 1.0v
5. (GND) 0.0v
6. (Low gate) 0.0v
7. (High Gate) 1.0v.
8. (Vcc) 15.0v

These readings were taken with he TV powered on. And the backlight flickering.

I'm attaching pictures of the board. And also of the IC with pin 1 marked. I hope I didn't mark it upside down? This is for reference so you know where my readings are.

When I removed the heatsink I scraped some of the lamination on the GND planes.

Should I go ahead and look at the back light circuit next? What are all these ICs in the repair kit for sim I don't even see on my board. I tried googling the designators but no luck finding any useful information.

[budm]

Re: Vizio/LG E420VT

The kit you bought is for Vizio ADTVA2419AAY power supply board: https://www.shopjimmy.com/vizio-adtv...upply-unit.htm
But you indicated that your board is Vizio 080GL19X01LT
https://www.shopjimmy.com/vizio-080g...led-board.htm#
That is why the designators do not match, there is no repair kit, but they do have repair service for it.https://www.shopjimmy.com/vizio-080g...ir-service.htm

[TechShui]

Re: Vizio/LG E420VT

Okay but can't I fix it? Or is there no service manual?

I do see repair kits for it on eBay... What do you think of the voltages of the PFC all are okay? 15v at VCC.

[budm]

Re: Vizio/LG E420VT

1) But right now the PFC IC you put in is not the same P/N so we have no idea if it is compatible or not.
2) What other parts in the kit that you installed?
3) Check resistance of PFC Diodes D401, 401A.
4) Edited: skipped this one.
5) Edited: skipped this one.
5) No service manual for this power supply board.

BTW, HS01G is NOT PFC IC! It is SMPS IC https://cdn.badcaps-static.com/pdfs/...855a94d0bf.pdf
What is the P/N s printed on the PFC IC on your board (I already asked in my post #9)? LD7591??? We need to get that info correct first.

[TechShui]

Re: Vizio/LG E420VT

1) But right now the PFC IC you put in is not the same P/N so we have no idea if it is compatible or not.
2) What other parts in the kit that you installed?
3) Check resistance of PFC Diodes D401, 401A.
4) Edited: skipped this one.
5) Edited: skipped this one.
5) No service manual for this power supply board.

BTW, HS01G is NOT PFC IC! It is SMPS IC https://cdn.badcaps-static.com/pdfs/...855a94d0bf.pdf
What is the P/N s printed on the PFC IC on your board (I already asked in my post #9)? LD7591??? We need to get that info correct first.

In post #9 you said IC601 is probably the PFC controller. It is in fact HS01G. Datasheet tells it's a half-bridge resonance controller.

The voltages in post #10 are with the original HS01G installed.

Datasheet: (same as the one you attached)

Only parts from the kit I installed are:
Blue ceramic cap at C604A
Main fuse was replaced.
And yes I did mess up and installed the kit's PFC at the location for what we now know is the SMPS.
TV turns on with it and LED stays white for a second then goes back to standby, Probably shorted that new PFC chip since it's in the wrong spot. Oof.

But I can put back the original HS01G that's probably not the problem anyways. Like it's voltages in post #10 are fine, right?

EDIT:

1) I will check the diode's resistance tomorrow for D401 and D401A. Then report findings.
2) main filter caps don't spike to 400 just stay at 154-160 even when the TV is on.
3) I traced this 154v line to IC150 which is under a heatsink and I can't read it. But I still suspect that could be PFC? I will try removing the heatsink to read the P/N tomorrow.

[budm]

Re: Vizio/LG E420VT

"In post #9 you said IC601 is probably the PFC controller. It is in fact HS01G. Datasheet tells it's a half-bridge resonance controller."
It is 100% wrong! That HS01G (IC9801 in the kit) cannot be IC601 PFC IC, so no way you can put HS01G SMPS IC in the PFC section where IC601 is in your board.

IC150 on your board is the SMPS IC for the standby power supply.
IC9801 in the kit you boayght is HS01G SMPS IC used in this board for the 24V SMPS section: https://www.shopjimmy.com/vizio-adtv...pply-unit.htm#
You get the IC's of your board mixed up with the KIT that is not made for your board. Find the IC601 that you remove and look at it again, or buy the replacement board.
What else that you replaced on your board with the wrong parts you received?
Pictures provided by shopjimmy.

[TechShui]

Re: Vizio/LG E420VT

"In post #9 you said IC601 is probably the PFC controller. It is in fact HS01G. Datasheet tells it's a half-bridge resonance controller."
It is 100% wrong! That HS01G (IC9801 in the kit) cannot be IC601 PFC IC, so no way you can put HS01G SMPS IC in the PFC section where IC601 is in your board.

IC150 on your board is the SMPS IC for the standby power supply.
IC9801 in the kit you boayght is HS01G SMPS IC used in this board for the 24V SMPS section: https://www.shopjimmy.com/vizio-adtv...pply-unit.htm#
You get the IC's of your board mixed up with the KIT that is not made for your board. Find the IC601 that you remove and look at it again, or buy the replacement board.
What else that you replaced on your board with the wrong parts you received?
Pictures provided by shopjimmy.

Again, IC601 is Infineon HS01G. That's is the ORIGINAL chip that was at that location. Are you saying it should not be there? It didn't look tampered with in the slightest, so that is what the board came with.

The kit which is wrong for this set, has no Infineon chips whatsoever. It does have an LD7571. Which is marked IC9801. You are the one thinking the chip is there when it's not. The PFC on this board is somewhere else, not at IC601.

Weird thing is there's not many ICs on this board, IC101 and U201 are also both SMPS chips.

IC150 is W6053N, another power mosfet. There is a repair kit for this TV on eBay from a San Antonio seller maybe I should email him and ask if he can confirm IC601. Can I ask why are you surprised it's not a PFC?

[budm]

Re: Vizio/LG E420VT

Are these pictures below are the exact match of what you have? That is what I am going by. May be we are not looking at the same board, same board assembly.
https://www.badcaps.net/forum/attach...8&d=1556430033
https://www.badcaps.net/forum/attach...6&d=1556427641
https://www.badcaps.net/forum/attach...7&d=1556430033
Per pictures, it has have TWO SMPS IC on the hot side:
IC150 (TO-220 casing attached to the heatsink) for the standby power supply.
IC101 (SMD) for 12V and 24V.
IC601 (SMD) IS the PFC IC, which you cannot put in SMPS IC is its place, period.

So where in the world did you come up the IC150 as the MOSFET? https://cdn.badcaps-static.com/pdfs/...c988f8f0b9.pdf

So the your kit https://www.shopjimmy.com/vizio-adtv...for-e420vt.htm you bought from Shopjimmy, correct?
Just 4 IC's + other parts.
IC9801 SMD as LD7571 (PFC IC)
IC9301 through-hole for standby power supply.
IC9101 SMD for 12V, 24V power supply.
IC9803 ????
So the bottom line is that you never remove IC601 from your board, correct? And you are the original owner of the TV.
And what happen to the resistance readings of the two PFC diodes?
BTW, looking at your picture, it looks like you replaced the PFC diode and the two PFC MOSFET's.
https://www.badcaps.net/forum/attach...7&d=1556430033
The soldering does not look good.

[budm]

Re: Vizio/LG E420VT

Based on pictures from shopjimmy, this is what I see and from the look of it, it looks like the pin out matched PFC LD7591, the connections do not match ICE1HS01G-DS as far as I can see from the board layout.
So based on your reading of IC601 using pin out of LD7591: It looks like it is dead based on spec sheet. But at this point you should verify with the kit seller as to what the IC601 should be your board, make sure to provide them with pictures and board P/N.
1. (INV) 0.0v.
2. (Comp) 5.0v
3. (Ramp) 0.0v
4. (CS) 1.0v
5. (ZCD) 0.0v
6. (GND) 0.0v
7. (OUT, Gate drive) 1.0v.
8. (Vcc) 15.0v
BTW, you can also look at the application circuit of the LD7591, it looks pretty close to what IC601 is connected.