Vizio E422VA not turning on

[tibimakai]

Re: Vizio E422VA not turning on

OK. I have supplied the 5V externally and the power supply shows 1.37A and the voltmeter 2.6V.
It seems like the mainboard is pulling down the voltage. Both boards are doing the same thing, this is the weird part.
I have tried disconnecting everything else going to the mainboard and the load does not change.
I still have to check the resistance to the ground.

[hienton2]

Re: Vizio E422VA not turning on

Did you check p.on from main. I doubt your second main is bad.

[tibimakai]

Re: Vizio E422VA not turning on

I haven't yet, but since the standby is low, that can't be good.

[hienton2]

Re: Vizio E422VA not turning on

Feel hot on any components on main?

[tibimakai]

Re: Vizio E422VA not turning on

I didn't have time to check for heating parts, but PS_ON doesn't work and resistance from standby to ground is 2Kohm.

[tibimakai]

Re: Vizio E422VA not turning on

The 5V standby voltage should be able to power a car 6V bulb? Without anything connected, it shows 5.17V.
The power supply can't handle this bulb, it just drops to 0V.
I think, that there is a "weak" part in the power supply and can't handle the main board.

[budm]

Re: Vizio E422VA not turning on

It should be able to handle 5 Ohms Load (1A) without problem. Try heating the cap around the standby power supply section, especially the startup cap to see if will run properly.

[tibimakai]

Re: Vizio E422VA not turning on

I will do that in the morning.
We are dealing here, with a surge.

[hienton2]

Re: Vizio E422VA not turning on

I will make a modified circuit to make it works. must figure R1 R2 to make output
about 4v (on) 0v(off)

[budm]

Re: Vizio E422VA not turning on

That will invert the Active HI signal from the main board, the PS_ON signal must be >2V = ON, <1V = OFF. The output at the Collector is inverted from the Input at the Base.
I am not sure how the circuit is related to this thread. Also the signal is DC so you cannot put cap on the Base pin.

[hienton2]

Re: Vizio E422VA not turning on

Ok Budm. May be I am wrong here. It is an inverter a hi on p.o will make a low
out.I just want to make a higher voltage for his p.o from main board.As I think
his psu board is good.

[tibimakai]

Re: Vizio E422VA not turning on

I have reconnected all the wires into there connectors and plugged in all the connectors in there places.
Place the voltmeter into the ground and 5V standby and after plugging in, it shows 2.5V and (very)slowly creeps up. By heating the secondary capacitors and the ones before the standby transformer on the primary side, the voltage went up slightly faster. After a while, a white LED started to turn on brighter and brighter. It reached 4.3V after a long wait(had dinner).
The TV, still did not turn on.
The board in the picture is not my TVs board, I'm trying to point out the place, that seemed the most affected by the heat.

[budm]

Re: Vizio E422VA not turning on

I believe that cap in red circle and the other 2 close to it are part of start-up/running caps, just replace them will be faster to find out if they are bad or not, they should be replaced sooner or later any way as part of the caps kit.
What is the P/N of that 8-pin IC close to it?

[tibimakai]

Re: Vizio E422VA not turning on

Unfortunately, I don't have a 100uf/50V capacitor, only 25V. Need to place an order.
They use Elite capacitors in the PS, I have never heard about this brand.
Should I replace all of them?

[Agent24]

Re: Vizio E422VA not turning on

Probably a good idea, Elite aren't that great

[budm]

Re: Vizio E422VA not turning on

Can I see the bottom side of the board? Also take the DC Voltage readings right at the two legs of those 3 caps, and also the P/N of that 8-pin SMPS IC next to the cap in red circle.

[tibimakai]

Re: Vizio E422VA not turning on

Sorry about not providing enough info, I was busy in the last three weeks, I had a visitor at my place.
Today, I will get everything that you have asked.

[tibimakai]

Re: Vizio E422VA not turning on

TV it's running, yeah!!
I have replaced the circled capacitor(100uf/50V) and the orange one(330uf) after the transformer(in secondary part of the PS).
I'm not sure now which fixed the problem, because the capacitor meter is not showing a constant value, but I'm suspecting the orange capacitor.
At the bottom of the power supply where the capacitor is and the diode on a heating it's yellow, it runs to hot and dried out this capacitor. Capacitor meter shows a value around 157 out of circuitry and it should be 330uf.
Easy fix.
The problem is, that I have purchased a main board for $130 and is not needed.
Thanks for the help.

[Agent24]

Re: Vizio E422VA not turning on

Good to hear!

[gtoira]

Re: Vizio E422VA not turning on

I have this same problem exactly, but changing the caps made no difference. For tibimakai: Do you still have that board you bought and do you want to sell it? I don't know how to contact you or how this forum works. My email is iragoodberg at hotmail. Let me know how I can discuss my issue with you.