LCD, is this really where we're at?

"Mikeapollo" wrote in message
o.uk...
Stephen Wolstenholme wrote:

If in doubt... For quality go for a plasma or stick with a CRT.

Oh, I think I would. Who makes a 32" plasma (1080)?

Probably been dropped a few times en route. I do not think the low strength
of the lcd construction helps in this respect.
Brian

--
Brian Gaff -
Note:- In order to reduce spam, any email without 'Brian Gaff'
in the display name may be lost.
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"Grumps" wrote in message
...
Hello

I've been very happy with my old Sony CRT, but (even thought it's still
working fine, and the picture looks good) it might be time for something a
little bigger and HD. I'm looking at 32" at the moment. This'll be
primarily for TV, as there's a projector for decent movies.

I have 4 LCD monitors at home 17" or bigger, 1280x1024 or greater. Of
these, one has a dead pixel (R,G&B), one has a stuck sub-pixel, and one
has a whole column stuck white (this'll be a warranty repair).
At work I have two monitors. One has a dead green sub-pixel.

A colleague recenly bought a 32" LG LCD TV/monitor. It had a stuck red
sub-pixel. This TV was collected by LG, waited in their repair dept for 3
weeks, then was sent back as "beyond repair". It was replaced by the
store. The replacement has a stuck blue and green sub-pixel.

Are there ANY manufacturers that can actually supply a fully functional
panel?!

Actually, you do not get the same sort of fault on a CRT. There is no way,
for example for a crt dot to be on when its a dark area of picture. It is
this problem which causes the errors to show up so well on lcds.

Brian

--
Brian Gaff -
Note:- In order to reduce spam, any email without 'Brian Gaff'
in the display name may be lost.
Blind user, so no pictures please!
"Dave Plowman (News)" wrote in message
...
In article ,
Grumps wrote:
I've been very happy with my old Sony CRT, but (even thought it's still
working fine, and the picture looks good) it might be time for something
a little bigger and HD. I'm looking at 32" at the moment. This'll be
primarily for TV, as there's a projector for decent movies.

I have 4 LCD monitors at home 17" or bigger, 1280x1024 or greater. Of
these, one has a dead pixel (R,G&B), one has a stuck sub-pixel, and one
has a whole column stuck white (this'll be a warranty repair). At work
I have two monitors. One has a dead green sub-pixel.

A colleague recenly bought a 32" LG LCD TV/monitor. It had a stuck red
sub-pixel. This TV was collected by LG, waited in their repair dept for
3 weeks, then was sent back as "beyond repair". It was replaced by the
store. The replacement has a stuck blue and green sub-pixel.

Are there ANY manufacturers that can actually supply a fully functional
panel?!

If you examine a CRT as carefully you'll likely find faults too.

--
*Middle age is when it takes longer to rest than to get tired.

Dave Plowman London SW
To e-mail, change noise into sound.

"Brian Gaff" wrote in message
m...
Actually, you do not get the same sort of fault on a CRT. There is no way,
for example for a crt dot to be on when its a dark area of picture. It is
this problem which causes the errors to show up so well on lcds.

Brian

--
Brian Gaff -
Note:- In order to reduce spam, any email without 'Brian Gaff'
in the display name may be lost.
Blind user, so no pictures please!
"Dave Plowman (News)" wrote in message
...
In article ,
Grumps wrote:
I've been very happy with my old Sony CRT, but (even thought it's still
working fine, and the picture looks good) it might be time for something
a little bigger and HD. I'm looking at 32" at the moment. This'll be
primarily for TV, as there's a projector for decent movies.

I have 4 LCD monitors at home 17" or bigger, 1280x1024 or greater. Of
these, one has a dead pixel (R,G&B), one has a stuck sub-pixel, and one
has a whole column stuck white (this'll be a warranty repair). At work
I have two monitors. One has a dead green sub-pixel.

A colleague recenly bought a 32" LG LCD TV/monitor. It had a stuck red
sub-pixel. This TV was collected by LG, waited in their repair dept for
3 weeks, then was sent back as "beyond repair". It was replaced by the
store. The replacement has a stuck blue and green sub-pixel.

Are there ANY manufacturers that can actually supply a fully functional
panel?!

If you examine a CRT as carefully you'll likely find faults too.

--
*Middle age is when it takes longer to rest than to get tired.

Dave Plowman London SW
To e-mail, change noise into sound.



black marker pen. the way to reduce unwanted bright pixels.

In article ,
Brian Gaff wrote:
Actually, you do not get the same sort of fault on a CRT. There is no
way, for example for a crt dot to be on when its a dark area of
picture. It is this problem which causes the errors to show up so well
on lcds.

Indeed. On a CRT it will be dark rather than bright. But there
nevertheless.

--
*Everyone has a photographic memory. Some just don't have film*

Dave Plowman London SW
To e-mail, change noise into sound.

"Dave Plowman (News)" wrote in message
...
In article ,
Brian Gaff wrote:
Actually, you do not get the same sort of fault on a CRT. There is no
way, for example for a crt dot to be on when its a dark area of
picture. It is this problem which causes the errors to show up so well
on lcds.

Indeed. On a CRT it will be dark rather than bright. But there
nevertheless.

--
*Everyone has a photographic memory. Some just don't have film*

Dave Plowman London SW
To e-mail, change noise into sound.

on Sony Trinitron crts there are 2 horizontal lines which I hated and took
ages to learn to ignore.

then of course there was the sets that suffered from shadow mask distortion
with bright pictures. My 26" JVC the first S VHS set was a real problem.
but the hidef picture ( it said so on the box) was really sharp . in excess
of 11 MHz video display with suitable input. and the purity problem was not
a problem if the white was not toooooo big.

Most BW sets had a dead spot in the middle of the screen.


Gary

In article ,
says...


on Sony Trinitron crts there are 2 horizontal lines which I hated and took
ages to learn to ignore.


These were the support wires for the grille (which replaced the shadow
mask in the Trinitron)


Most BW sets had a dead spot in the middle of the screen.


You must be really ancient to remember something like that!

(Or is it perceived wisdom?)

Early tubes had a straight gun which fired both electrons and ions at
the screen. When the set was switched off and the scanning collapsed,
there was still plenty of EHT left which continued to attract the beam.
(The 'traditional' white spot effect.)

Ions are much heavier than electrons so the the ion beam wasn't focussed
when it hit the screen but, inertia due to the added weight meant that
they ploughed into the phosphor coating with destructive force which,
after a time, caused the so called ion-burn.

However, this was resolved fairly early on by using a bent gun in the
CRT. A magnet assembly was used to bend the electron beam back towards
the screen but, because of their greater inertia, the ions didn't bend
enough and ploughed harmlessly into the metal innards of the electron
gun.

Later on - mid 50s - manufacturers introduced an aluminised coating
behind the phosphor to reflect previously wasted light back through the
screen. This layer was found to be strong enough to resist ion damage so
CRTs went back to having straight guns again.

Just how well do you remember the ion-burn problem?

--

Terry

"Terry Casey" wrote in message
om...
In article ,
says...


on Sony Trinitron crts there are 2 horizontal lines which I hated and
took
ages to learn to ignore.


These were the support wires for the grille (which replaced the shadow
mask in the Trinitron)


Most BW sets had a dead spot in the middle of the screen.


You must be really ancient to remember something like that!

(Or is it perceived wisdom?)

Early tubes had a straight gun which fired both electrons and ions at
the screen. When the set was switched off and the scanning collapsed,
there was still plenty of EHT left which continued to attract the beam.
(The 'traditional' white spot effect.)

Ions are much heavier than electrons so the the ion beam wasn't focussed
when it hit the screen but, inertia due to the added weight meant that
they ploughed into the phosphor coating with destructive force which,
after a time, caused the so called ion-burn.

However, this was resolved fairly early on by using a bent gun in the
CRT. A magnet assembly was used to bend the electron beam back towards
the screen but, because of their greater inertia, the ions didn't bend
enough and ploughed harmlessly into the metal innards of the electron
gun.

Later on - mid 50s - manufacturers introduced an aluminised coating
behind the phosphor to reflect previously wasted light back through the
screen. This layer was found to be strong enough to resist ion damage so
CRTs went back to having straight guns again.

Just how well do you remember the ion-burn problem?

--

Terry

I used to work on BW monitors in the 70-80 and they all eventually got a
spot. but it was a long time unless a scan fault or some power fault that
caused the spot suppression system to fail. details have faded but there was
a bias used to prevent burn.

In article ,
says...

"Terry Casey" wrote in message
om...
In article ,
says...


on Sony Trinitron crts there are 2 horizontal lines which I hated and
took
ages to learn to ignore.


These were the support wires for the grille (which replaced the shadow
mask in the Trinitron)


Most BW sets had a dead spot in the middle of the screen.


You must be really ancient to remember something like that!

(Or is it perceived wisdom?)

Early tubes had a straight gun which fired both electrons and ions at
the screen. When the set was switched off and the scanning collapsed,
there was still plenty of EHT left which continued to attract the beam.
(The 'traditional' white spot effect.)

Ions are much heavier than electrons so the the ion beam wasn't focussed
when it hit the screen but, inertia due to the added weight meant that
they ploughed into the phosphor coating with destructive force which,
after a time, caused the so called ion-burn.

However, this was resolved fairly early on by using a bent gun in the
CRT. A magnet assembly was used to bend the electron beam back towards
the screen but, because of their greater inertia, the ions didn't bend
enough and ploughed harmlessly into the metal innards of the electron
gun.

Later on - mid 50s - manufacturers introduced an aluminised coating
behind the phosphor to reflect previously wasted light back through the
screen. This layer was found to be strong enough to resist ion damage so
CRTs went back to having straight guns again.

Just how well do you remember the ion-burn problem?

--

Terry

I used to work on BW monitors in the 70-80 and they all eventually got a
spot. but it was a long time unless a scan fault or some power fault that
caused the spot suppression system to fail. details have faded but there was
a bias used to prevent burn.

The intention was to discharge the EHT as quickly as possible. One very
simple but effective method used when all TVs had a 'live' chassis was
to connect the bottom end of the brightness control network to chassis
via the MAINS side of the neutral section of the DPST mains switch. When
the set was switched of, this floated and immediately turned up the
brightness so that the charge was dispersed while the scans were
collapsing!

IIRC another method, which didn't need a 'live' chassis, used a VDR in
the earthy leg of the brightness control network.

My recollection is that CRT burn was very rare and it would also have
been much less noticeable than the large circular shadow that resulted
from ion-burn.

--

Terry

Terry Casey wrote:
.)

Ions are much heavier than electrons so the the ion beam wasn't focussed
when it hit the screen but, inertia due to the added weight meant that
they ploughed into the phosphor coating with destructive force which,
after a time, caused the so called ion-burn.

Not disputing this but where do the ions come from?
If there is a hard vacuum in the tube, then surely ionised gas (ions)
cannot exist.
A.