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Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems. |
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#1
Posted to sci.electronics.repair,sci.electronics.misc,alt.tv.tech.hdtv
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NEC plasma TV: what's the cause of image "solarizing"?
This 8 year old NEC PX-42MP3A plasma has some -- what I'd call solarizing
effects. See this photo of the screen: http://i41.tinypic.com/21c9ul1.jpg Note the fine blue and red outlines on the cheeks of both faces. These surround the highlights on the faces (cheekbones). (Disregard all the horrid horiz. and vert. lines -- those are due to moire effect with the camera. They're absent on the TV screen). I've adjusted all the controls (bright, contr, sharp). At extreme low light + low contrast the effects are minimized but still visible. The specs in the manual say that the color reproduction is "RGB 256 color steps 1677millions colors". Is this something caused by poor design? Failing electronics? Or...? This display is new to me, so I have no history to report. Thanks, -- John English |
#2
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NEC plasma TV: what's the cause of image "solarizing"?
Hi!
I don't see anything on that screen to suggest a failure in the set. I'm inclined to say that the set is eight years old, and in that time, the technology has improved a lot and become cheaper. It almost looks to me like the TV is being asked to resolve colors that it can't quite manage to resolve. This could be due to a limitation of the plasma panel--displays like this typically need to resolve eight bits of color data for each color, but not all do. Some only resolve six bits or fewer, leaving some colors that can't be precisely represented on the screen. William |
#3
Posted to sci.electronics.repair,sci.electronics.misc,alt.tv.tech.hdtv
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NEC plasma TV: what's the cause of image "solarizing"?
"John E." wrote in message obal.net...
This 8 year old NEC PX-42MP3A plasma has some -- what I'd call solarizing effects. See this photo of the screen: http://i41.tinypic.com/21c9ul1.jpg Note the fine blue and red outlines on the cheeks of both faces. These surround the highlights on the faces (cheekbones). (Disregard all the horrid horiz. and vert. lines -- those are due to moire effect with the camera. They're absent on the TV screen). I've adjusted all the controls (bright, contr, sharp). At extreme low light + low contrast the effects are minimized but still visible. The specs in the manual say that the color reproduction is "RGB 256 color steps 1677millions colors". Is this something caused by poor design? Failing electronics? Or...? This display is new to me, so I have no history to report. Thanks, -- John English Is this same problem present on all input signals? Is the photo you posted taken from a DVD, a live cable or satellite signal etc? |
#4
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NEC plasma TV: what's the cause of image "solarizing"?
Is this same problem present on all input signals?
Yes. Is the photo you posted taken from a DVD, a live cable or satellite signal etc? DVD (not Blu-Ray). Thanks, -- John English |
#5
Posted to sci.electronics.repair,sci.electronics.misc,alt.tv.tech.hdtv
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NEC plasma TV: what's the cause of image "solarizing"?
"John E." wrote in message
obal.net... This 8 year old NEC PX-42MP3A plasma has some -- what I'd call solarizing effects. See this photo of the screen: http://i41.tinypic.com/21c9ul1.jpg Note the fine blue and red outlines on the cheeks of both faces. These surround the highlights on the faces (cheekbones). (Disregard all the horrid horiz. and vert. lines -- those are due to moire effect with the camera. They're absent on the TV screen). I've adjusted all the controls (bright, contr, sharp). At extreme low light + low contrast the effects are minimized but still visible. The specs in the manual say that the color reproduction is "RGB 256 color steps 1677millions colors". Is this something caused by poor design? Failing electronics? Or...? This display is new to me, so I have no history to report. Thanks, -- John English The panel is getting old. Possibly a Vs adjustment would fix it, at least temporarily. Mark Z. |
#6
Posted to sci.electronics.repair,sci.electronics.misc,alt.tv.tech.hdtv
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NEC plasma TV: what's the cause of image "solarizing"?
That isn't solarization. It's more like posterization.
It looks, in part, as if the display cannot create sufficiently small brightness steps to render fine shadings. By modern standards, 8-bits per color would be considered rather skimpy. My gut feeling, though, is that the set is defective, most likely whatever chip or board does the D-to-A conversion. |
#7
Posted to sci.electronics.repair,sci.electronics.misc,alt.tv.tech.hdtv
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NEC plasma TV: what's the cause of image "solarizing"?
The panel is getting old.
When you say "panel" do you mean the plasma tubes themselves? Not an electronic component? Possibly a Vs adjustment would fix it, at least temporarily. This is a power supply voltage adjustment? -- John English |
#8
Posted to sci.electronics.repair,sci.electronics.misc,alt.tv.tech.hdtv
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NEC plasma TV: what's the cause of image "solarizing"?
New developments:
http://i41.tinypic.com/2wei4af.jpg Close-up: http://i43.tinypic.com/280k4uo.jpg Same effect seen on all inputs. Could this be a power supply problem? -- John English |
#9
Posted to sci.electronics.repair,sci.electronics.misc,alt.tv.tech.hdtv
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NEC plasma TV: what's the cause of image "solarizing"?
"John E." wrote in message
obal.net... New developments: http://i41.tinypic.com/2wei4af.jpg Close-up: http://i43.tinypic.com/280k4uo.jpg Same effect seen on all inputs. Could this be a power supply problem? -- John English Not sure if it's the PS, but if that's how it looks with different sources, it definitely needs repair. |
#10
Posted to sci.electronics.repair,sci.electronics.misc,alt.tv.tech.hdtv
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NEC plasma TV: what's the cause of image "solarizing"?
On Wed, 8 Apr 2009 18:43:41 -0700, John E.
wrote: This 8 year old NEC PX-42MP3A plasma[...] It's 8 years old. Splurge for a new TV already. A_C |
#11
Posted to sci.electronics.repair,sci.electronics.misc,alt.tv.tech.hdtv
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NEC plasma TV: what's the cause of image "solarizing"?
It's 8 years old. Splurge for a new TV already.
I have a 50-inch Pioneer. It is beautiful. Ignoramuses making statements like "spend the money, already" just show their immaturity. There are many reasons for resurrecting an old display: as a hobby; to keep it out of the landfill; to give to an older friend who can't afford one; just to mention a few. Although it's first on your lips, 'cheapskate" is not always the reason... -- John English |
#12
Posted to sci.electronics.repair,sci.electronics.misc,alt.tv.tech.hdtv
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NEC plasma TV: what's the cause of image "solarizing"?
I didn't read the original post. What is the history, be brief.
To summarize: I just received this monitor, so I don't know its distant history, but... The image will "solarize", it seems to be compressed in a small range of contrast. See this image: http://i41.tinypic.com/21c9ul1.jpg Note the blue and red outlines of the highlights (cheekbones & noses). These highlights seem to "sparkle". (The horiz & vert lines are just moire effect with the camera; ignore these.) Then this morning when I turned it on, I got these images: http://i41.tinypic.com/2wei4af.jpg Close-up: http://i43.tinypic.com/280k4uo.jpg Same effect seen on all inputs. -- John English |
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