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Discussion Starter · #1 ·
I bought this Plasma TV in 2010 and i hardly ever use it, has *Maybe* 5hrs of use on it, at the MOST! My issue im having with it is i have SNOW all over screen or what some people i keep seeing calling it "Sparkles". I've watched hours of youtube videos to see that most people are saying it is a PSU issue due to failing caps, and what not.. I have pulled the PSU and being that this tv has virtually only 5hrs or less of run time, everything inside it looks perfect. A neighbor of mine de-soldered a few caps on the PSU, and checked them, they were perfect, so he soldered what he took out right back in. I see I can get a new PSU for this TV for 50-75$ new, but also came across a video on youtube where a service tech said to make sure the Setpots are adjusted to manufactures set points. I took a picture of the sticker that tells me the correct voltage for "Ve" and Vsus" AC voltage readings, but my question is this; Where are the contact points to put my meter leads to check the voltage on these setpoints? And I CAN NOT find the setpot for "Ve" only for "Vsus" but i took a pic of the only other 2 adjustable setpots, so maybe you all can point me in the right direction? Thank you SO VERY MUCH, and look forward to see if someone might have the time to help me :T

http://i675.photobucket.com/albums/vv113/newls1/0519131650b_zps0e60f3e3.jpg
http://i675.photobucket.com/albums/vv113/newls1/0519131650_zps8fbd83ec.jpg
http://i675.photobucket.com/albums/vv113/newls1/0519131650a_zpsb9f82dc0.jpg

http://i675.photobucket.com/albums/vv113/newls1/0519131651_zps7679c9fc.jpg
 

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Your capacitors look fine.

The image problem you describe could be the fault of corroding wires connecting the plasma panel to the mainboards; but that's just an educated guess.
 

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What kind of source are you using? When you say caps were tested, which ones and how? This is not a typical symptom for a power supply, but possible. One would need a schematic to be sure about the test points.
 

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Discussion Starter · #4 ·
Your capacitors look fine.

The image problem you describe could be the fault of corroding wires connecting the plasma panel to the mainboards; but that's just an educated guess.
What kind of source are you using? When you say caps were tested, which ones and how? This is not a typical symptom for a power supply, but possible. One would need a schematic to be sure about the test points.
Ive tried all input sources... HDMI, RCA coax, and straight up cable input, all show same snow on screen
 

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Discussion Starter · #5 · (Edited)
Also, thank you guys for your replies so far... I have a youtube vid that shows my exact issue, but this websites spam filter wont let me post the link until i hit 5 posts :(


UPDATE::: Here is the video that shows the issue

 

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I bought this Plasma TV in 2010 and i hardly ever use it, has *Maybe* 5hrs of use on it, at the MOST! My issue im having with it is i have SNOW all over screen or what some people i keep seeing calling it "Sparkles". I've watched hours of youtube videos to see that most people are saying it is a PSU issue due to failing caps, and what not.. I have pulled the PSU and being that this tv has virtually only 5hrs or less of run time, everything inside it looks perfect. A neighbor of mine de-soldered a few caps on the PSU, and checked them, they were perfect, so he soldered what he took out right back in. I see I can get a new PSU for this TV for 50-75$ new, but also came across a video on youtube where a service tech said to make sure the Setpots are adjusted to manufactures set points. I took a picture of the sticker that tells me the correct voltage for "Ve" and Vsus" AC voltage readings, but my question is this; Where are the contact points to put my meter leads to check the voltage on these setpoints? And I CAN NOT find the setpot for "Ve" only for "Vsus" but i took a pic of the only other 2 adjustable setpots, so maybe you all can point me in the right direction? Thank you SO VERY MUCH, and look forward to see if someone might have the time to help me :T
That link in your last post is an interesting little introduction to power supply repair. I cringed when I saw all the hacks from the previous repairs.

I usually replace with a higher voltage cap when physically possible. You can go a little higher capacitance, too, but not a lot.

Apparently a bad power supply can cause the sparkles. But there can be other causes.

http://www.jopezu.com/plasma.htm

http://www.badcaps.net/forum/showthread.php?t=10657

Note that these caps can store a lethal charge, even after they are turned off for quite a while. I usually short across a cap with a test lead prior to doing anything, to discharge the cap. I connect the lead to one side, then just brush it against the other, bracing myself for a spark. Usually, they put a high value resistor across the cap to discharge the cap, but I never assume that.

Although your caps are not bulging, as far as I can see, they still could be defective. Or there could be a bad solder joint or a crack in the circuit board. Or it could be a defective cap. Electrolytic caps are not easy to test. I used to take an old analog voltmeter, set it to resistance at the lowest value, then connect it across the cap, then quickly reserve the leads. If the voltmeter pegged for a second, then I suspected the cap was good. But that is not proof. A better test is to check for AC across the cap, but we do not know what level of AC is OK in this circuit.

Here is a good detailed link about adjusting the voltage in a Pana power supply. But it scares me to do this with power on. If you are not an expert, you could turn it off, move the pot a little, then turn it back on, keeping in mind those nasty caps store voltage.

http://www.justanswer.com/tv-repair...howing-noise-sparkling-pixels-dark-black.html
 

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Keep capacitance the same, voltage and temperature can be increased with out harm. Changing capacitance can alter functionality of certain circuits. As for my personal preference, I'd worry about higher temperature capacitors and stick with stock voltage.
 

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Discussion Starter · #8 ·
That link in your last post is an interesting little introduction to power supply repair. I cringed when I saw all the hacks from the previous repairs.

I usually replace with a higher voltage cap when physically possible. You can go a little higher capacitance, too, but not a lot.

Apparently a bad power supply can cause the sparkles. But there can be other causes.

http://www.jopezu.com/plasma.htm

http://www.badcaps.net/forum/showthread.php?t=10657

Note that these caps can store a lethal charge, even after they are turned off for quite a while. I usually short across a cap with a test lead prior to doing anything, to discharge the cap. I connect the lead to one side, then just brush it against the other, bracing myself for a spark. Usually, they put a high value resistor across the cap to discharge the cap, but I never assume that.

Although your caps are not bulging, as far as I can see, they still could be defective. Or there could be a bad solder joint or a crack in the circuit board. Or it could be a defective cap. Electrolytic caps are not easy to test. I used to take an old analog voltmeter, set it to resistance at the lowest value, then connect it across the cap, then quickly reserve the leads. If the voltmeter pegged for a second, then I suspected the cap was good. But that is not proof. A better test is to check for AC across the cap, but we do not know what level of AC is OK in this circuit.

Here is a good detailed link about adjusting the voltage in a Pana power supply. But it scares me to do this with power on. If you are not an expert, you could turn it off, move the pot a little, then turn it back on, keeping in mind those nasty caps store voltage.

http://www.justanswer.com/tv-repair...howing-noise-sparkling-pixels-dark-black.html
Thank you very much for that informative reply....
 

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You should use a large high impedance resistor to short out a capacitor, it is going to be much safer than a swift and rapid discharge using a piece of raw metal.
Do you mean a high resistance resistor?

Impedance is an AC measurement. Impedance is something a coil would have while being almost a short to DC. One could connect a high impedance resistor across a cap and have a short, which is the same thing as "using a piece of raw metal" except that one might burn out the coil. Electrolytic caps store DC energy, therefore a resistor is appropriate. As I mentioned in my first note, most (all.) circuits should have a resistor across the power supply to drain any stored energy. Ones I have seen are in the range of 2 mega ohms.

But you are right, one should use a resistor to slowly drain the power away. I don't know what value could be universal since the amount of power stored depends on the amount of capacitance and the voltage. In order to be safe, one might want a 5 watt 1 mega ohm resistor and leave it connected for several minutes in order for it to drain.

That said, I have never worked with a technician who actually does that. I have always seen, and used the grounded screwdriver trick. 99% of the time, nothing happens. Sometimes we just skip it and get an occasional spark (followed by a curse), which is not recommended.

I have seen electricians figure out which house breaker is on a circuit by shorting the black and white wires on a 120 VAC line. Now that is something that I would never do! 20 A at 120 VAC has a lot more power than the small current at 50 VDC or less in a stored in a cap.
 

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Impedance is not really an AC measurement. It is resistance accounting for ac components. Really impedance is d.c. resistance (purely magnitude) with phase.

Every resistor has resistance and impedance. For d.c. they are equivalent (zero phase).

The statement "One could connect a high impedance resistor across a cap and have a short" is confusing and misleading. A short is low resistance, which will necessarily be low impedance as well. It could be that you are confusing inductance and impedance. An inductor will have impedance to a.c. but behave as a short for d.c., but it should be referred to as an inductor, not a high impedance resistor.
 

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it should be referred to as an inductor, not a high impedance resistor.
I agree. The reference to "high impedance resistor" was not originally mine. The previous poster suggested this term. Since the purpose of this proposed resistor was to drain the stored energy in a cap, and no AC is involved, one normally selects a "high value resistor", not a "high impedance resistor". Impedance and resistance are the same in DC, and one does not specify DC resistance as "impedance".
 
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