Re: Vizio TV E3D420VX, No picture, power led on+blink 1time+V logo shown=>turn off
Hi. Bud. Your comments make me confused....
djju
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Last Activity: 05-11-2017, 11:29 AM
Joined: 12-16-2015
Location: North Little Rock
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Re: Vizio TV E3D420VX, No picture, power led on+blink 1time+V logo shown=>turn off
You mean, even though main board is replaced by new, the problem still remains. Therefore, it's not main board problem?...Leave a comment:
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Re: Vizio TV E3D420VX, No picture, power led on+blink 1time+V logo shown=>turn off
Thanks, Bud. But DKWILL's symptom is with audio. With audio means definitely main board works properly. That mean the initial stage of main board is passed and works main function but only screen problem.
My problem is different. My problem is no picture, no sound, only showing v logo and completely power and backlight off. I hear no sound after having problem.
By the way, thanks bud. I will ask him where to get the new board. I am going to buy new main...Leave a comment:
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Re: Vizio TV E3D420VX, No picture, power led on+blink 1time+V logo shown=>turn off
Yeah, exactly...I wanted to figure out how the reset signal on main board works when power is on, but I couldn't find which part gives the reset on main board. Do you know that? Could you let me know that part gives it?
I really want to check the reset and clock first but I have no oscilloscope in my house, so it is really hard to figure out this....Last edited by djju; 12-23-2015, 09:16 PM.Leave a comment:
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Re: Vizio TV E3D420VX, No picture, power led on+blink 1time+V logo shown=>turn off
In post#55 case, (LAMP connected. DIM disconnected)
DIM on main board side = low (but fluctuating)
DIM on power supply side = 3.3V
Post#55 + DIM wire connection (i.e. LAMP connected, DIM connected)
DIM 0V -> 3.3V -> 0V
Power and backlight on and goes off.
In my thought, DIM might be pulled up on 3.3V on power supply.
Without connection, DIM stays on 3.3V and power & backlight stay...Leave a comment:
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Re: Vizio TV E3D420VX, No picture, power led on+blink 1time+V logo shown=>turn off
That is my question too. You know, I already checked all LDO, STEPDOWN, and PowerMOSFET output and it was good. I think going PSON down to 0V mean there would be short to GND, but after checking, I couldn't find the short point.
I'm worried that if I purchase the new main board, that board would be caused same problem because of external impact.........Leave a comment:
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Re: Vizio TV E3D420VX, No picture, power led on+blink 1time+V logo shown=>turn off
<Test Result> DCV of PSON on main board when PSON & ON/OFF cutting with 5V pull-up.
before power on: 0V
Power on: 3.3V -> 0V
Power and backlight stay on....Leave a comment:
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Re: Vizio TV E3D420VX, No picture, power led on+blink 1time+V logo shown=>turn off
Then, this problem can be separated to 100% main board problem?...Leave a comment:
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Re: Vizio TV E3D420VX, No picture, power led on+blink 1time+V logo shown=>turn off
"But I didn't lie" means that I want to say it comes just from multimeter. Don't get me wrong, please.
I don't want to stop solving problem. I want to know what makes LAMP high or low. I'm an engineer too. I am satisfied everything should be clear....Leave a comment:
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Re: Vizio TV E3D420VX, No picture, power led on+blink 1time+V logo shown=>turn off
I'm sorry but I can't understand your comment.
As I understand, your comment is that LAMP cannot be 3.3V because is driven by source of transistor 5V. Is it right?
But I didn't lie. I show the result in video and just say as what DCV is shown in multimeter. It is 3.19V.
And in previous experiment, after cutting DIM, the symptom is same even though LAMP is low.
Aren't my postings enough information for you to say it is caused by main...Last edited by djju; 12-22-2015, 01:15 PM.Leave a comment:
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Re: Vizio TV E3D420VX, No picture, power led on+blink 1time+V logo shown=>turn off
Peak is same as my first experiment. 1.105V when power on...Leave a comment:
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Re: Vizio TV E3D420VX, No picture, power led on+blink 1time+V logo shown=>turn off
1. You mean, check PSON on main board side even though it is cutted and PSON on power supply side is pulled up?
2. LAMP is Low even it still connected.
3. No. I couldn't get the picture....Leave a comment:
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Re: Vizio TV E3D420VX, No picture, power led on+blink 1time+V logo shown=>turn off
Hi! Bud!
Test results after cutting DIM.
1. PSON, ON/OFF, DIM cutting & LAMP connected.
PSON & ON/OFF 3K pull-up to 5V
[URL="http://youtu.be/6IVKPcAbIaA"]http://youtu.be/6IVKPcAbIaA[/URL]
=> Power & Backlight are on, and stay on.
2. Only DIM cutting & PSON,ON/OFF, & LAMP connected.
PSON by button (signal from main board)
[URL="http://youtu.be/OVmsUszjhis"]http://youtu.be/OVmsUszjhis[/URL]...Leave a comment:
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Re: Vizio TV E3D420VX, No picture, power led on+blink 1time+V logo shown=>turn off
Hi! Bud!
Test results after cutting DIM.
1. PSON, ON/OFF, DIM cutting & LAMP connected.
PSON & ON/OFF 3K pull-up to 5V
[URL="http://youtu.be/6IVKPcAbIaA"]http://youtu.be/6IVKPcAbIaA[/URL]
=> Power & Backlight are on, and stay on.
2. Only DIM cutting & PSON,ON/OFF, & LAMP connected.
PSON by button (signal from main board)
[URL="http://youtu.be/OVmsUszjhis"]http://youtu.be/OVmsUszjhis[/URL]...Leave a comment:
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Re: Vizio TV E3D420VX, No picture, power led on+blink 1time+V logo shown=>turn off
Hi Bud,
Please see the picture and compare the value of yours.
The resistor value between G6584 STEPDOWN DC/DC out for core voltage and GND is to low. It's only 18.1 ohm.
Is it yours as well? Sometimes, DC/DC buck output port has very low impedance to GND but it looks to low. Please check with yours. Please....Leave a comment:
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Re: Vizio TV E3D420VX, No picture, power led on+blink 1time+V logo shown=>turn off
Hi Bud,
Please see this video. [URL="http://youtu.be/kkaOQi8KWz8"]http://youtu.be/kkaOQi8KWz8[/URL]
1. Power & baclight are on as long as power is supplied without connection to main board and with 3k pullup on PSON & ON/OFF
2. With connection to main board and 3k pullup on PSON & ON/OFF with cutting wire, then power supplied. Power & backlight was on almost less than a second and off both immediately.Re:...Leave a comment:
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Re: Vizio TV E3D420VX, No picture, power led on+blink 1time+V logo shown=>turn off
I'm sorry, but it's true. Please see this youtube link. [URL="http://youtu.be/6V7tXe7iCeY"]http://youtu.be/6V7tXe7iCeY[/URL]
You can see power & backlight off immediately after power on & backlight on.
And check the picture. I cut PSON & ON/OFF wires.
In my case, I use 3K instead of 1K which I have. (I think it's no problem)
When I was testing the power supply using the resistor, no connection to main board and putting...Leave a comment:
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Re: Vizio TV E3D420VX, No picture, power led on+blink 1time+V logo shown=>turn off
No, backlight goes off as well. Sorry for no enough information. I have edited and uploaded youtube....Last edited by djju; 12-21-2015, 12:52 PM.Leave a comment:
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Re: Vizio TV E3D420VX, No picture, power led on+blink 1time+V logo shown=>turn off
Result of post#23: [URL="https://youtu.be/6V7tXe7iCeY"]https://youtu.be/6V7tXe7iCeY[/URL]
1.cut wires of PSON & ON/OFF
2.measure LAMP (power supply and main board side both)
R1. power on and backlight on
R2. DCV of LAMP goes over 2V and immediately power & backlight off.
R3. At that time, no power_white_led is no blinking.
R4. No more stays than no cut off PSON & ON/OFF wire. Immediately power &...Leave a comment:
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Re: Vizio TV E3D420VX, No picture, power led on+blink 1time+V logo shown=>turn off
Hi, Bud.
Before the experiment of post 23, I have a question about it.
In a summarization:
1. LAMP is out of power b/d => (True: 'cause it is connected to cathode of diode)
2. 5V, 12V generation has no problem => (True)
3. Inverter has no problem => (True: 'cause it stays on when PSON & ON/OFF are 5V pulled up forcibly)
4. LAMP is low when PSON & ON/OFF are 5V pulled up forcibly. => (??? Which part makes LAMP...Leave a comment:
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