S
Sylvia Else
Guest
http://tinyurl.com/yz3eko4
How does a CRT end up with a vertical line of dead pixels?
Sylvia.
How does a CRT end up with a vertical line of dead pixels?
Sylvia.
Navigation
Install the app
How to install the app on iOS
Follow along with the video below to see how to install our site as a web app on your home screen.
Note: This feature may not be available in some browsers.
More options
You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an alternative browser.
You should upgrade or use an alternative browser.
A
Adrian C
Guest
Sylvia Else wrote:
--
Adrian C
Faulty digital frame buffer.http://tinyurl.com/yz3eko4
How does a CRT end up with a vertical line of dead pixels?
--
Adrian C
B
baron
Guest
Sylvia Else Inscribed thus:
straight vertical line then its unlikely to be the crt. Possibly some
artifact of the video feed... maybe ?
--
Best Regards:
Baron.
I've never seen a crt with a line of dead anything ! If its a deadhttp://tinyurl.com/yz3eko4
How does a CRT end up with a vertical line of dead pixels?
Sylvia.
straight vertical line then its unlikely to be the crt. Possibly some
artifact of the video feed... maybe ?
--
Best Regards:
Baron.
P
PeterD
Guest
On Wed, 04 Nov 2009 22:22:06 +1100, Sylvia Else
<sylvia@not.at.this.address> wrote:
driver. I'd guess it is not going to be worth trying to fix, something
is gone in the digital section(s).
<sylvia@not.at.this.address> wrote:
It processes the signal as digital then converts to analog for the CRThttp://tinyurl.com/yz3eko4
How does a CRT end up with a vertical line of dead pixels?
Sylvia.
driver. I'd guess it is not going to be worth trying to fix, something
is gone in the digital section(s).
J
Jim Yanik
Guest
PeterD <peter2@hipson.net> wrote in
news:9t13f5h9pp3a5mkborrbkjsvjgoucj7bm0@4ax.com:
--
Jim Yanik
jyanik
at
localnet
dot com
news:9t13f5h9pp3a5mkborrbkjsvjgoucj7bm0@4ax.com:
some chip in the frame memory?On Wed, 04 Nov 2009 22:22:06 +1100, Sylvia Else
sylvia@not.at.this.address> wrote:
http://tinyurl.com/yz3eko4
How does a CRT end up with a vertical line of dead pixels?
Sylvia.
It processes the signal as digital then converts to analog for the CRT
driver. I'd guess it is not going to be worth trying to fix, something
is gone in the digital section(s).
--
Jim Yanik
jyanik
at
localnet
dot com
R
Ron
Guest
Jim Yanik wrote:
Ron
are usually horizontal)PeterD <peter2@hipson.net> wrote in
news:9t13f5h9pp3a5mkborrbkjsvjgoucj7bm0@4ax.com:
On Wed, 04 Nov 2009 22:22:06 +1100, Sylvia Else
sylvia@not.at.this.address> wrote:
http://tinyurl.com/yz3eko4
How does a CRT end up with a vertical line of dead pixels?
Sylvia.
It processes the signal as digital then converts to analog for the CRT
driver. I'd guess it is not going to be worth trying to fix, something
is gone in the digital section(s).
some chip in the frame memory?
Could it possibly be a stabilising wire as in the Trinitrons(I know they
Ron
D
D Yuniskis
Guest
Sylvia Else wrote:
pixels" in this CRT -- though only one is probably visible
(luck?).
There are two (3?) wires that cross the screen (usually horizontally
but since this is a wider aspect ratio screen, they might be
oriented vertically) used to stabilize the aperture grill.
It doesn't. :> I suspect there are *two* "lines of deadhttp://tinyurl.com/yz3eko4
How does a CRT end up with a vertical line of dead pixels?
pixels" in this CRT -- though only one is probably visible
(luck?).
There are two (3?) wires that cross the screen (usually horizontally
but since this is a wider aspect ratio screen, they might be
oriented vertically) used to stabilize the aperture grill.
D
Dave Platt
Guest
In article <hcs008$poa$2@news.eternal-september.org>,
baron <baron.nospam@linuxmaniac.nospam.net> wrote:
Instead, it uses a shadow grid - a bunch of very fine parallel
vertical wires, stretched from top to bottom.
An occasional fault in a Trinotron is for one of the shadow wires to
end up out of position. If I recall properly, this can happen if
somebody uses an external degausser - the magnetic field can shove one
wire across the one next to it. This will cause a subtle vertical
stripe to appear on the screen.,. looks rather like a row of dead
pixels.
I think there's a Field Engineering Repair procedure for this...
rapping sideways on the case, with just the right amount of force, to
jar the stuck wires apart and allow the displaced one to snap back to
its correct position. I don't know how much force is required.
One can sometimes see this effect even on a perfectly good
Trinotron tube... I think that in some models there are vertical
reinforcing rods in the grid assembly which can produce a shadow on
the tube.
--
Dave Platt <dplatt@radagast.org> AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!
baron <baron.nospam@linuxmaniac.nospam.net> wrote:
It's a Trinitron tube. This type of CRT doesn't use a shadow mask.http://tinyurl.com/yz3eko4
How does a CRT end up with a vertical line of dead pixels?
I've never seen a crt with a line of dead anything ! If its a dead
straight vertical line then its unlikely to be the crt. Possibly some
artifact of the video feed... maybe ?
Instead, it uses a shadow grid - a bunch of very fine parallel
vertical wires, stretched from top to bottom.
An occasional fault in a Trinotron is for one of the shadow wires to
end up out of position. If I recall properly, this can happen if
somebody uses an external degausser - the magnetic field can shove one
wire across the one next to it. This will cause a subtle vertical
stripe to appear on the screen.,. looks rather like a row of dead
pixels.
I think there's a Field Engineering Repair procedure for this...
rapping sideways on the case, with just the right amount of force, to
jar the stuck wires apart and allow the displaced one to snap back to
its correct position. I don't know how much force is required.
One can sometimes see this effect even on a perfectly good
Trinotron tube... I think that in some models there are vertical
reinforcing rods in the grid assembly which can produce a shadow on
the tube.
--
Dave Platt <dplatt@radagast.org> AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!
B
Baron
Guest
Dave Platt wrote:
in a Trinitron tube. I knew about the two horizontal ones. I can
actually see those in my screen.
--
Best Regards:
Baron.
Dave: Thanks for those notes. I wasn't aware of the vertical wire gridIn article <hcs008$poa$2@news.eternal-september.org>,
baron <baron.nospam@linuxmaniac.nospam.net> wrote:
http://tinyurl.com/yz3eko4
How does a CRT end up with a vertical line of dead pixels?
I've never seen a crt with a line of dead anything ! If its a dead
straight vertical line then its unlikely to be the crt. Possibly some
artifact of the video feed... maybe ?
It's a Trinitron tube. This type of CRT doesn't use a shadow mask.
Instead, it uses a shadow grid - a bunch of very fine parallel
vertical wires, stretched from top to bottom.
An occasional fault in a Trinotron is for one of the shadow wires to
end up out of position. If I recall properly, this can happen if
somebody uses an external degausser - the magnetic field can shove one
wire across the one next to it. This will cause a subtle vertical
stripe to appear on the screen.,. looks rather like a row of dead
pixels.
I think there's a Field Engineering Repair procedure for this...
rapping sideways on the case, with just the right amount of force, to
jar the stuck wires apart and allow the displaced one to snap back to
its correct position. I don't know how much force is required.
One can sometimes see this effect even on a perfectly good
Trinotron tube... I think that in some models there are vertical
reinforcing rods in the grid assembly which can produce a shadow on
the tube.
in a Trinitron tube. I knew about the two horizontal ones. I can
actually see those in my screen.
--
Best Regards:
Baron.
S
Sylvia Else
Guest
Adrian C wrote:
would it be for?
Sylvia.
I'd be surprised if a television like that had a frame buffer. WhatSylvia Else wrote:
http://tinyurl.com/yz3eko4
How does a CRT end up with a vertical line of dead pixels?
Faulty digital frame buffer.
would it be for?
Sylvia.
A
Adrian C
Guest
Sylvia Else wrote:
--
Adrian C
The set features a digital tuner.Adrian C wrote:
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?
--
Adrian C
S
Sylvia Else
Guest
Adrian C wrote:
mode, I think the seller would have said so.
Sylvia.
Fair point. Still, if the pixels were dead only in digital receptionSylvia Else wrote:
Adrian C wrote:
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?
The set features a digital tuner.
mode, I think the seller would have said so.
Sylvia.
B
Bob Larter
Guest
Sylvia Else wrote:
--
W
. | ,. w , "Some people are alive only because
\|/ \|/ it is illegal to kill them." Perna condita delenda est
---^----^---------------------------------------------------------------
Good question. I've only ever seen a fault like that on an LCD panel.http://tinyurl.com/yz3eko4
How does a CRT end up with a vertical line of dead pixels?
--
W
. | ,. w , "Some people are alive only because
\|/ \|/ it is illegal to kill them." Perna condita delenda est
---^----^---------------------------------------------------------------
S
Samuel M. Goldwasser
Guest
Sylvia Else <sylvia@not.at.this.address> writes:
buffers.
However, I would be skeptical that a digital failure would result
in a vertical line fault in a non-flat panel TV, though might be
possible.
Has anyone contacted the seller to get a more detailed description of
the appearance of the "dead pixels" or a photo? Also, a CRT fault
will stay fixed on the screen regardlerss of the mode or any adjustments
while soemthing in the digital processing would almost cerrtainly not.
--
sam | Sci.Electronics.Repair FAQ: http://www.repairfaq.org/
Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
+Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm
| Mirror Sites: http://www.repairfaq.org/REPAIR/F_mirror.html
Important: Anything sent to the email address in the message header above is
ignored unless my full name AND either lasers or electronics is included in the
subject line. Or, you can contact me via the Feedback Form in the FAQs.
It has a DTV tuner, thus it has digital storage and one or more frameAdrian 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?
buffers.
However, I would be skeptical that a digital failure would result
in a vertical line fault in a non-flat panel TV, though might be
possible.
Has anyone contacted the seller to get a more detailed description of
the appearance of the "dead pixels" or a photo? Also, a CRT fault
will stay fixed on the screen regardlerss of the mode or any adjustments
while soemthing in the digital processing would almost cerrtainly not.
--
sam | Sci.Electronics.Repair FAQ: http://www.repairfaq.org/
Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
+Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm
| Mirror Sites: http://www.repairfaq.org/REPAIR/F_mirror.html
Important: Anything sent to the email address in the message header above is
ignored unless my full name AND either lasers or electronics is included in the
subject line. Or, you can contact me via the Feedback Form in the FAQs.
S
Sylvia Else
Guest
Bob Larter wrote:
expect it to produce a line of bright pixels next to the dark ones -
electrons from more than one cathode reaching the phosphor.
Sylvia.
The stuck shadow wire concept seems reasonably plausible, though I'dSylvia 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.
expect it to produce a line of bright pixels next to the dark ones -
electrons from more than one cathode reaching the phosphor.
Sylvia.
W
William Sommerwerck
Guest
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.
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.
P
PeterD
Guest
On Thu, 05 Nov 2009 18:13:57 +1100, Sylvia Else
<sylvia@not.at.this.address> wrote:
'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)
<sylvia@not.at.this.address> wrote:
Read the specifications, the video is digital to the CRT. Basically aAdrian 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.
'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)
S
Sjouke Burry
Guest
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.
M
Meat Plow
Guest
On Thu, 05 Nov 2009 22:27:53 +0100, Sjouke Burry
<burrynulnulfour@ppllaanneett.nnll>wrote:
<burrynulnulfour@ppllaanneett.nnll>wrote:
How about pic in pic?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.
B
Bob Larter
Guest
Sylvia Else wrote:
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
---^----^---------------------------------------------------------------
End users aren't usually very good at describing symptoms accurately.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.
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
---^----^---------------------------------------------------------------