Vizio E422VA not turning on

[tibimakai]

The previous owner said that they had a storm and right after the storm the TV would not turn on anymore. Most likely a surge.
I have manged to force the PS on and it's all good there, backlight turns on, all the voltages are there.
If I lug in the mainboard connector, the standby voltage is pulled down to 2.59V.
Can I find the problem component on the mainboard, or I should just get a another one?
A thermal fuse how should show on the meter, mine shows 0.5 ohm.
Any ideas would be appreciated.
This would be the mainboard(picture from shopjimmy):
http://www.shopjimmy.com/media/catal...acb5k00503.jpg

[stj]

Re: Vizio E422VA not turning on

fix it.
trace the standby voltage and see what it connects to.
it's probably not much.

[tibimakai]

Re: Vizio E422VA not turning on

I have found a voltage regulator type of component(three pins on one side and two on the other) and the markings are EKAON.
I can't find anything about it, on the net.
Pin #3 and #4 have short, I don't know if it's OK or not though.

[stj]

Re: Vizio E422VA not turning on

foto?

[tibimakai]

Re: Vizio E422VA not turning on

The two pins marked with small orange arrows show 2.59V(short with Ohm meter). They also seem like, input and output pins to me.
I have replaced a couple days ago a very similar component on a Sony TV which it was a voltage regulator that had a control ON/OFF function as well. It was regulating 5v to 3.3V. Maybe it's the same part?
Here it is:

[stj]

Re: Vizio E422VA not turning on

could be a regulator.
can you remove it cleanly?

[tibimakai]

Re: Vizio E422VA not turning on

Yes, I can. What should I do after that?

[stj]

Re: Vizio E422VA not turning on

see if the short is on the part, or the pcb.

[tibimakai]

Re: Vizio E422VA not turning on

I have removed it and the voltages did not change, so there is something else then, but there are not to many components around there to go bad.
The main processor is warming up also. What if it's damaged already?

[stj]

Re: Vizio E422VA not turning on

you didnt anser the question.

was the part you removed shorted, or was the short still on the board?

[tibimakai]

Re: Vizio E422VA not turning on

I haven't measured the part, but after removing the part, there it was still 2.6V at both pads.
Most likely something else is pulling down the voltage.
Could be one of the capacitors?

[stj]

Re: Vizio E422VA not turning on

could be anything,
but you still need to check the part & pads on the board.

[tibimakai]

Re: Vizio E422VA not turning on

Finally I have found a mainboard for $109.
I have installed it expecting the TV to turn on and be OK.
To my surprise, nothing happened.
I'm measuring the standby 5V and it drops with this board to as soon as I connecting it.
If I unplug it, it shows 5.1V.
If I force the PS to turn on, it turns on and backlight stays on as it should.
I really need some help here.
Not sure, what to make of this one.
The second mainboard, to have the same issue, it's almost impossible.
TV went bad, after a storm.

[tibimakai]

Re: Vizio E422VA not turning on

Nobody has any ideas?

[audiofreak19]

Re: Vizio E422VA not turning on

Well either the main board you got is bad or it's not in the main board. If your standby voltage isn't up to spec then I would bet its one of the voltage regulators in the main board.

[tibimakai]

Re: Vizio E422VA not turning on

I have purchased it from tvpartsguy and they guaranty that the board is good, but I will contact them about this, though.
What is weird, that how come both boards show the same exact symptom?

[audiofreak19]

Re: Vizio E422VA not turning on

There is a short or bad regulator I think in both of them. If it drops when plugged in. Then there is a bad regulator most likely

[Ltank]

Re: Vizio E422VA not turning on

Let see if i got this right. The PS 5stby is 5 or 5.1 vdc with no main board connected.
You replaced the main board and it, too loads down the 5vdc stby. What was the resistance on the main board pin in reference to chasis ground? It should be at least several hundred ohms as not load down the PS. If the PS is loaded down easily then the regulator on the PS 5vdc circuitry is the problem. Th check what resistance is bad take these steps. measure the main board reisistance on that pin referenced to chasis gnd.
That would be the low end of your test. Get a vaiable resistor (POT) at least double that resistance and load the PS while measuring the voltage. When that voltage drops, remove power and check the resistace on the pot. It will give you and idea when it starts breaking down and confirm the problem is in the PS

[budm]

Re: Vizio E422VA not turning on

Try using 5 Ohms 10W as the load to simlulate 1A of current draw on the 5V line to see if it can handle 1A load, I do not know the spec of the 5VSTBY, but it should be able to provide 1A @5VDC at least.

[hienton2]

Re: Vizio E422VA not turning on

Have an good external 5v. connect to 5v in of main board .see it load down the 5v?. then use p.on of mainboard to turn on the power supply . I hope it works.

Must have good ground connection. external and tv