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| William Sommerwerck... |
 Posted: Thu Nov 05, 2009 8:39 am |
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I'm not even sure what "dead pixels on a CRT" actually means.
I've seen one or two CRTs with missing phosphor spots, but they're extremely
rare, as they wouldn't normally get through QC.
A vertical line of them is hard to believe. And as for tangled
aperture-grille wires... I've seen this on a 36" Sony (in fact, we discussed
it several months ago), but all it did was badly screw up the purity.
It goes without saying that if the "defect" comes and goes, or moves with
the program material, it can't be in the tube.
A photograph would be really useful. |
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| PeterD... |
| Posted: Thu Nov 05, 2009 9:38 am |
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On Thu, 05 Nov 2009 18:13:57 +1100, Sylvia Else
<sylvia at (no spam) not.at.this.address> wrote:
[quote]Adrian C wrote:
Sylvia Else wrote:
http://tinyurl.com/yz3eko4
How does a CRT end up with a vertical line of dead pixels?
Faulty digital frame buffer.
I'd be surprised if a television like that had a frame buffer. What
would it be for?
Sylvia.
[/quote]
Read the specifications, the video is digital to the CRT. Basically a
'cross-over' model on the way to full (LCD etc.) digital. Frame
buffers are not unusual in these types of sets (the wide-screen
variety) |
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| Sjouke Burry... |
| Posted: Thu Nov 05, 2009 4:27 pm |
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Sylvia Else wrote:
[quote]Adrian C wrote:
Sylvia Else wrote:
http://tinyurl.com/yz3eko4
How does a CRT end up with a vertical line of dead pixels?
Faulty digital frame buffer.
I'd be surprised if a television like that had a frame buffer. What
would it be for?
Sylvia.
Freeze pic/digital zoom in/out.[/quote] |
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| Meat Plow... |
| Posted: Thu Nov 05, 2009 4:41 pm |
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On Thu, 05 Nov 2009 22:27:53 +0100, Sjouke Burry
<burrynulnulfour at (no spam) ppllaanneett.nnll>wrote:
[quote]Sylvia Else wrote:
Adrian C wrote:
Sylvia Else wrote:
http://tinyurl.com/yz3eko4
How does a CRT end up with a vertical line of dead pixels?
Faulty digital frame buffer.
I'd be surprised if a television like that had a frame buffer. What
would it be for?
Sylvia.
Freeze pic/digital zoom in/out.
[/quote]
How about pic in pic? |
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| Bob Larter... |
| Posted: Thu Nov 05, 2009 10:18 pm |
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Sylvia Else wrote:
[quote]Bob Larter wrote:
Sylvia Else wrote:
http://tinyurl.com/yz3eko4
How does a CRT end up with a vertical line of dead pixels?
Good question. I've only ever seen a fault like that on an LCD panel.
The stuck shadow wire concept seems reasonably plausible, though I'd
expect it to produce a line of bright pixels next to the dark ones -
electrons from more than one cathode reaching the phosphor.
[/quote]
End users aren't usually very good at describing symptoms accurately.
It's entirely possible that the fault is actually as you've suggested.
I'd try degaussing the middle of the line, in the hopes of shaking the
wire loose.
--
W
. | ,. w , "Some people are alive only because
\|/ \|/ it is illegal to kill them." Perna condita delenda est
---^----^--------------------------------------------------------------- |
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| ... |
| Posted: Thu Nov 05, 2009 11:06 pm |
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On Nov 5, 7:18 pm, Bob Larter <bobbylar... at (no spam) gmail.com> wrote:
[quote]Sylvia Else wrote:
Bob Larter wrote:
Sylvia Else wrote:
http://tinyurl.com/yz3eko4
How does a CRT end up with a vertical line of dead pixels?
Good question. I've only ever seen a fault like that on an LCD panel.
The stuck shadow wire concept seems reasonably plausible, though I'd
expect it to produce a line of bright pixels next to the dark ones -
electrons from more than one cathode reaching the phosphor.
End users aren't usually very good at describing symptoms accurately.
It's entirely possible that the fault is actually as you've suggested.
I'd try degaussing the middle of the line, in the hopes of shaking the
wire loose.
--
W
. | ,. w , "Some people are alive only because
\|/ \|/ it is illegal to kill them." Perna condita delenda est
---^----^---------------------------------------------------------------
[/quote]
Get a rubber mallet and hit it in the face - pretty hard. If the
aperture grill lines are twisted, that will set them straight. I've
done this after a nasty trip with an external degaussing coil.
G² |
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| William Sommerwerck... |
| Posted: Fri Nov 06, 2009 7:17 am |
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[quote]It's entirely possible that the fault is actually as you've suggested.
I'd try degaussing the middle of the line, in the hopes of shaking
the wire loose.
Get a rubber mallet and hit it in the face - pretty hard. If the
aperture grill lines are twisted, that will set them straight. I've
done this after a nasty trip with an external degaussing coil.
[/quote]
Simply lifting the set and dropping it gently (???) might fix the problem.
This happend to my Sony WEGA in March when it was moved from the LR to the
BR. The splotch disappeared, and has not come back. |
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