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sysvr4
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Last Activity: 01-30-2013, 09:43 AM
Joined: 11-28-2012
Location: Nashville, TN
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  • sysvr4
    replied to Vizio VA19L Won't Power On
    in Troubleshooting TVs and Video Sources
    Re: Vizio VA19L Won't Power On

    Thanks again guys... I tested on the old board, and it *does* appear that VCC is shorted to ground on the IC. I can't compare yet to the new board because that TV is now in use in our guest room

    As soon as I get an opportunity I'll compare the two and report back here, but it looks like I'll be ordering and replacing that IC soon.

    Thank and Merry Christmas, everyone!
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  • sysvr4
    replied to Vizio VA19L Won't Power On
    in Troubleshooting TVs and Video Sources
    Re: Vizio VA19L Won't Power On

    Thanks... what range has a shot at working? Maybe I've got a dead board here from something else I can pull one from.

    Actually, just found the following on an old xbox power board I have:

    - 25V 47uF
    - 25V 100uF
    - 16V 1000uF
    See more | Go to post
    Last edited by sysvr4; 12-22-2012, 07:29 AM.

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  • sysvr4
    replied to Vizio VA19L Won't Power On
    in Troubleshooting TVs and Video Sources
    Re: Vizio VA19L Won't Power On

    budm, thanks again. Those kinds of explanations are so helpful, much more than the simple check this or check that... like I said, I'm trying to actively learn this stuff and I appreciate you taking the time to explain!

    I haven't torn apart the working TV again yet to test the IC voltages, but you had asked earlier if I had any capacitors on hand... as it turns out I was going through some old drawers in the workshop today and found some.

    Now, I have no idea how old these are, but they're all still new in packages... anyway,...
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  • sysvr4
    replied to Vizio VA19L Won't Power On
    in Troubleshooting TVs and Video Sources
    Re: Vizio VA19L Won't Power On

    budm: No other caps currently on hand... well, except the one on the new board, but I'm not quite brave enough to pull that one off and use it to test

    tom66: Thank you... if someone can provide a bit of guidance on where those resistors are and how to test them, I'll gladly check that too.

    Thanks again guys...
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  • sysvr4
    replied to Vizio VA19L Won't Power On
    in Troubleshooting TVs and Video Sources
    Re: Vizio VA19L Won't Power On

    Yes, the startup cap had 0VDC across it. I don't have a capacitance tester yet, so that's all I've done with it so far.

    Good idea to replace both the IC and startup cap while I'm at it?
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  • sysvr4
    replied to Vizio VA19L Won't Power On
    in Troubleshooting TVs and Video Sources
    Re: Vizio VA19L Won't Power On

    Thanks budm, that's very helpful...

    Based on your description of the problem, is it also possible that the transformer isn't working properly to provide that 12V to the IC?

    Btw, new board works like a champ in the TV, tested it yesterday. I'm still going to attempt to fix this old board just for grins though...
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  • sysvr4
    replied to Vizio VA19L Won't Power On
    in Troubleshooting TVs and Video Sources
    Re: Vizio VA19L Won't Power On

    First, I should apologize for the delay... I have been traveling for the holidays and catching up on work. I've finally had a chance to get back to this project, and wanted to update everyone who's been helping on the progress.

    One thing I want to note is that a week or so ago, I was able to procure a replacement power board exactly like the one we've been discussing on eBay for a very reasonable price. I figured even if it did not fix the problem, I could use it as a tool to continue learning about how all this works, and I may even be...
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    Last edited by sysvr4; 12-17-2012, 12:56 PM.

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  • sysvr4
    replied to Vizio VA19L Won't Power On
    in Troubleshooting TVs and Video Sources
    Re: Vizio VA19L Won't Power On



    I'm getting some weird indications here on two different multimeters... testing for continuity between G-D, I get a very brief tone and flicker from the tester - less than 1 second - then nothing.

    No continuity between G-S and D-S......
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  • sysvr4
    replied to Vizio VA19L Won't Power On
    in Troubleshooting TVs and Video Sources
    Re: Vizio VA19L Won't Power On



    Ok, when I do that, I get 0VDC on all of them.



    Thanks again, that's helpful. So negative leg of the cap on the primary, and chassis on secondary. I'll try to remember that ...
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  • sysvr4
    replied to Vizio VA19L Won't Power On
    in Troubleshooting TVs and Video Sources
    Re: Vizio VA19L Won't Power On



    I get 0V on that one.

    And let me take this opportunity to say what a fantastic resource this board is. You guys don't know me from Adam, and so many folks are willing to take their time to help walk a guy like me through this... that's amazing! Thank you all very much...

    Truth be told, I'm starting to see why you guys enjoy this so much. I've even been on Amazon looking for good beginning electronics books the last few days. What a cool skill to have... anyway, thanks again!...
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  • sysvr4
    replied to Vizio VA19L Won't Power On
    in Troubleshooting TVs and Video Sources
    Re: Vizio VA19L Won't Power On



    You know it's bad when you have to tell a guy that to ensure you're getting accurate measurements. You know it's worse when he actually didn't know to do that and your suggestion makes a difference.

    Ok, remeasuring the 5V and 12V pads by the connector using the 907 capacitor negative, I get roughly 86VDC across each of them. Given the labels, that voltage seems way off to me, but at this point, it's obvious I don't know what the heck I'm talking about so I'll leave that for you guys to say...

    Also,...
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  • sysvr4
    replied to Vizio VA19L Won't Power On
    in Troubleshooting TVs and Video Sources
    Re: Vizio VA19L Won't Power On



    Sure thing, here ya go... I'm posting these offsite because they are 18 megapixel shots. That should allow zooming down to the molecular level

    [URL="http://www.soldmy.net/misc/back.JPG"]Full Back[/URL]

    [URL="http://www.soldmy.net/misc/front.JPG"]Full Front[/URL]

    [URL="http://www.soldmy.net/misc/back-1.JPG"]Back quarter 1[/URL]

    [URL="http://www.soldmy.net/misc/back-2.JPG"]Back quarter 2[/URL]

    [URL="http://www.soldmy.net/misc/back-3.JPG"]Back...
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  • sysvr4
    replied to Vizio VA19L Won't Power On
    in Troubleshooting TVs and Video Sources
    Re: Vizio VA19L Won't Power On



    Nope, still 0V on everything.

    Also, I don't know if this is helpful or not, but I noted the following on these two components...

    Green - 4 pins starting from north to south:

    0V, 110V, 0V, 110V

    Purple - 5 pins on the "west" side, starting north to south:

    110V, 110V, 110V, 0V, 0V

    On the "east" side, no voltage (AC or DC) on any of the pins....
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  • sysvr4
    replied to Vizio VA19L Won't Power On
    in Troubleshooting TVs and Video Sources
    Re: Vizio VA19L Won't Power On



    That's a negative. No DC voltage at all on any of the 5V or 12V pads, nor on standby.

    That narrow us down to the power supply?...
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  • sysvr4
    replied to Vizio VA19L Won't Power On
    in Troubleshooting TVs and Video Sources
    Re: Vizio VA19L Won't Power On



    Is there a way I can easily discern if the power supply is doing its job? In other words, how could I narrow down at least which board has the problem?...
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  • sysvr4
    replied to Vizio VA19L Won't Power On
    in Troubleshooting TVs and Video Sources
    Re: Vizio VA19L Won't Power On

    Why certainly!

    I don't see any fuses on the main board, but I may well have missed one. Let me know if any of you guys spot one...

    Also, let me know if I can post any other pictures that would be helpful. Thanks again!...
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  • sysvr4
    replied to Vizio VA19L Won't Power On
    in Troubleshooting TVs and Video Sources
    Re: Vizio VA19L Won't Power On

    Thanks for the response Mr Bill!

    I just checked as you described and I get 178V DC across that cap with the power plugged in.

    Amazingly, the TV suffered no physical damage at all that I can discern, either external or internal. My best guess at this point is that either the power or HDMI cords yanked on something internally when it fell, causing this problem, but that's just speculation at this point...

    Thanks again!
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  • sysvr4
    started a topic Vizio VA19L Won't Power On
    in Troubleshooting TVs and Video Sources

    Vizio VA19L Won't Power On

    Hello,

    I just found this forum while searching for ideas on how to repair this little Vizio TV I have. Please excuse me, but I have no TV repair experience, although I do own solder and desolder tools (and a multimeter), so I'm willing to give it a go Any help solving this is greatly appreciated...

    My daughter was playing around this TV the other day and caught a cord which sent it tumbling to the floor. My fault for not securing it properly... anyway, since that drop it won't power on. There's no standby light on either, but honestly, I'm not 100% sure it even...
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