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  #1  
Old 06-03-2018, 05:42 PM
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Boobtubeman Boobtubeman is offline
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Samsung plasma issue

30-35 minutes into running, it develops this blue dot pixelation shadows over light scenes.
If i use menus, youll see the ghost of them in blue pixels after the menu is exited...

My camera has a hard time showing them, but hopefully, you can get an idea from the pictures i tried to take..

Obviously somethings getting warm, but what? is this a typical issue with this model??

Thanks...

SR
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File Type: jpg blupixel.jpg (60.4 KB, 21 views)
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  #2  
Old 06-03-2018, 11:07 PM
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Boobtubeman Boobtubeman is offline
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I should add this is a full screen incident, its not isolated to the top or bottom.. Only way i could describe it is as blue snow in patches of scenes depending on the brightness of the scene, otherwise all other aspects of the picture is acceptable, its just annoying blue snow. Text and screen images seem to be working fine..
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  #3  
Old 06-03-2018, 11:57 PM
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MadMan MadMan is offline
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It looks like a loose connection to me. Good luck finding it. Could be a cracked solder joint or dirty plug on one of the boards. The telltale is that it happens when it warms up. Gets warm, metal expands, loses connection.
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  #4  
Old 06-04-2018, 12:49 AM
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Boobtubeman Boobtubeman is offline
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Yeah i was afraid of that.....

SR
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  #5  
Old 06-04-2018, 12:57 AM
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andy andy is offline
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The first thing to do is check the power supply voltages. Plasmas are very sensitive to their power supply voltages. The panel will have a sticker that tells you the correct voltages for the particular panel.

If those are ok, and you don't see any bulging caps, then it might be that the panel is starting to wear out. Sometimes you can improve them for a while by slightly tweaking some of the voltages by eye.
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  #6  
Old 06-04-2018, 09:01 PM
mbates14 mbates14 is offline
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your symptom is known as Maldischarge. its caused by drifting sustain voltages.

The main power supply creates two main voltages, Vs, and Va. VS is the sustain voltage, and Va is the addressing/buffer voltage.

However, the Y sustain board has a plethora of DC-DC converters that generate various other voltages for each state during the charge/discharge cycle. like -Vy, Vsc, etc...

These can drift around or have ripple from drying out/bad caps and do this.

Hell, I have seen some plasma TVs (I own one) that the DC-DC converters have gotten so bad, that they cycle. tick tick tick causing the picture to pulsate bright/dim/bright/dim where the picture goes into full brightness/perfect, and quickly fades to a screen full of maldischarge to almost an inverted image, and cycles back again. Like a strobe light. All from bad caps.
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Old 06-04-2018, 11:56 PM
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Boobtubeman Boobtubeman is offline
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I found a video online describing a similar problem and the guy traced it to 3 bad caps on the y sustain board. Looks like im going on a cap hunt....

SR
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  #8  
Old 06-05-2018, 05:21 PM
mbates14 mbates14 is offline
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Thats what I thought.

Older TVs I may have some knowledge gaps, but this modern stuff I know inside and out.
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