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Failures in antiglare coating on CRTs?

P

Philip Pemberton

Jan 1, 1970
0
Hi,
I've got a Mitsubishi DiamondPlus 74SB CRT monitor here, and it looks like
the anti-glare coating is coming away from the CRT glass. There are a number
of "pockmarks" in the coating, and along the top and bottom edges, a 5mm area
of the coating has disappeared, mainly around the plastic bezel. The monitor
is three years and three months old, manufactured 44th week of 2002, on my
desk on the 3rd of March 2003.

The only thing the CRT has ever been cleaned with is a microfibre cloth and
filtered water ("filtered" as in "gone through a ceramic/activated carbon
'pure water' filter"). On one occasion shortly after I got the monitor, I used
a CRT cleaning cloth (basically distilled water and a neutral detergent on a
microfibre pad) but that's it.

I had a Samsung Syncmaster 3 before the Mitsubishi, treated them the same
way and never had any issues with the coating - the Samsung is now nearly
eleven years old, the contrast pot is pretty much worn out, but the CRT is
still as bright as ever...

I'm at a loss to explain this, and the only answer I managed to get out of
NEC-Mitsubishi (well, NEC Display Systems) was - in effect - "it's your fault,
you can only cause that if you use chemicals to clean it."

I've also noticed that the CRT seems to have started picking up a very
nasty level of static charge - to the point where if my hand goes within a
quarter inch or so of the CRT (as it does when I switch it off), I get a
static-shock that's severe enough to cause my entire arm to spring backwards.
Is this likely to be related to the failure of the coating?

Can anyone shed some light on this annoying little issue?

Thanks.
 
J

JANA

Jan 1, 1970
0
I have seen on some monitors where the anti glare started to degrade. The
most common cause was during the coarse of its history, the screen has been
cleaned with a strong glass cleaner, especially one that contains ammonia,
or alcohol. Some types of anti glare coatings can be effected if the monitor
was kept in a humid environment.

As for getting shocks from the front of the CRT, check to see if the CRT
rear wall surface is properly grounded, and that the shield around it is
also properly grounded. Glass is normaly not conductive, therefore the
effect you are getting is from a dielectric pickup effect.

--

JANA
_____


Hi,
I've got a Mitsubishi DiamondPlus 74SB CRT monitor here, and it looks
like
the anti-glare coating is coming away from the CRT glass. There are a number
of "pockmarks" in the coating, and along the top and bottom edges, a 5mm
area
of the coating has disappeared, mainly around the plastic bezel. The monitor
is three years and three months old, manufactured 44th week of 2002, on my
desk on the 3rd of March 2003.

The only thing the CRT has ever been cleaned with is a microfibre cloth
and
filtered water ("filtered" as in "gone through a ceramic/activated carbon
'pure water' filter"). On one occasion shortly after I got the monitor, I
used
a CRT cleaning cloth (basically distilled water and a neutral detergent on a
microfibre pad) but that's it.

I had a Samsung Syncmaster 3 before the Mitsubishi, treated them the same
way and never had any issues with the coating - the Samsung is now nearly
eleven years old, the contrast pot is pretty much worn out, but the CRT is
still as bright as ever...

I'm at a loss to explain this, and the only answer I managed to get out
of
NEC-Mitsubishi (well, NEC Display Systems) was - in effect - "it's your
fault,
you can only cause that if you use chemicals to clean it."

I've also noticed that the CRT seems to have started picking up a very
nasty level of static charge - to the point where if my hand goes within a
quarter inch or so of the CRT (as it does when I switch it off), I get a
static-shock that's severe enough to cause my entire arm to spring
backwards.
Is this likely to be related to the failure of the coating?

Can anyone shed some light on this annoying little issue?

Thanks.
--
Phil. | Kitsune: Acorn RiscPC SA202 64M+6G
ViewFinder
[email protected] (valid!)| Cheetah: Athlon64 3200+ A8VDeluxeV2
512M+100G
http://www.philpem.me.uk/ | Tiger: Toshiba SatPro4600 Celeron700
256M+40G
No software patents! <http://www.eff.org/> /
<http://www.ffii.org/>
 
W

webpa

Jan 1, 1970
0
JANA said:
I have seen on some monitors where the anti glare started to degrade. The
most common cause was during the coarse of its history, the screen has been
cleaned with a strong glass cleaner, especially one that contains ammonia,
or alcohol. Some types of anti glare coatings can be effected if the monitor
was kept in a humid environment.

As for getting shocks from the front of the CRT, check to see if the CRT
rear wall surface is properly grounded, and that the shield around it is
also properly grounded. Glass is normaly not conductive, therefore the
effect you are getting is from a dielectric pickup effect.

--

JANA
_____


Hi,
I've got a Mitsubishi DiamondPlus 74SB CRT monitor here, and it looks
like
the anti-glare coating is coming away from the CRT glass. There are a number
of "pockmarks" in the coating, and along the top and bottom edges, a 5mm
area
of the coating has disappeared, mainly around the plastic bezel. The monitor
is three years and three months old, manufactured 44th week of 2002, on my
desk on the 3rd of March 2003.

The only thing the CRT has ever been cleaned with is a microfibre cloth
and
filtered water ("filtered" as in "gone through a ceramic/activated carbon
'pure water' filter"). On one occasion shortly after I got the monitor, I
used
a CRT cleaning cloth (basically distilled water and a neutral detergent on a
microfibre pad) but that's it.

I had a Samsung Syncmaster 3 before the Mitsubishi, treated them the same
way and never had any issues with the coating - the Samsung is now nearly
eleven years old, the contrast pot is pretty much worn out, but the CRT is
still as bright as ever...

I'm at a loss to explain this, and the only answer I managed to get out
of
NEC-Mitsubishi (well, NEC Display Systems) was - in effect - "it's your
fault,
you can only cause that if you use chemicals to clean it."

I've also noticed that the CRT seems to have started picking up a very
nasty level of static charge - to the point where if my hand goes within a
quarter inch or so of the CRT (as it does when I switch it off), I get a
static-shock that's severe enough to cause my entire arm to spring
backwards.
Is this likely to be related to the failure of the coating?

Can anyone shed some light on this annoying little issue?

Thanks.
--
Phil. | Kitsune: Acorn RiscPC SA202 64M+6G
ViewFinder
[email protected] (valid!)| Cheetah: Athlon64 3200+ A8VDeluxeV2
512M+100G
http://www.philpem.me.uk/ | Tiger: Toshiba SatPro4600 Celeron700
256M+40G
No software patents! <http://www.eff.org/> /
<http://www.ffii.org/>

Polymer anti-glare coatings degrade fairly rapidly when subjected to
direct sunlight or any other source of UV...such as florescent lamps or
quartz-halogen lamps. Some, but not all, anti-glare coatings are also
sufficiently conductive as to bleed-off the perfectly normal HV
(static) charge CRTs collect. After all, you are blasting 25-30 kV at
a non-conductive glass fishbowl. Try wiping the CRT with a sheet of
anti-static material intended for use in clothing dryers...wipe it on
you chair as well. Or spray it with "Static Guard" or something
similar. It is also possible that the glass from which your CRT is
blown does not have its full compliment of lead. If not, it has been
showering its front surface with X-Rays, thus degrading the anti-glare
coating (and your chances for a long line of descendents).

If you're worried, invest in an LCD monitor.
 
P

Philip Pemberton

Jan 1, 1970
0
webpa said:
Polymer anti-glare coatings degrade fairly rapidly when subjected to
direct sunlight or any other source of UV...such as florescent lamps or
quartz-halogen lamps.

Well bugger, that's probably what's done it. The monitor is at a 45-degree
angle to a window, and the evening sun usually hits it full-on (except when I
close the curtains, for obvious reasons).

Interesting that the same treatment didn't kill the SyncMaster. Are LCDs
susceptible to this problem as well?

It does say "keep the monitor at a 90-degree angle to light sources to prevent
reflections" in the manual, but there's nothing about the antiglare coating,
besides the usual massive list of chemicals to avoid using on it.
Some, but not all, anti-glare coatings are also
sufficiently conductive as to bleed-off the perfectly normal HV
(static) charge CRTs collect. After all, you are blasting 25-30 kV at
a non-conductive glass fishbowl. Try wiping the CRT with a sheet of
anti-static material intended for use in clothing dryers...wipe it on
you chair as well. Or spray it with "Static Guard" or something
similar.

Will do - thanks for the suggestion.
It is also possible that the glass from which your CRT is
blown does not have its full compliment of lead. If not, it has been
showering its front surface with X-Rays, thus degrading the anti-glare
coating (and your chances for a long line of descendents).

Possible, but highly unlikely.
If you're worried, invest in an LCD monitor.

I might, but not until the Mitsubishi either dies or decides to go silly on
me. Anyone know of any good brands of LCD? I was thinking along the lines of
Samsung, or maybe Sony if someone throws a huge bag of money my way...

Thanks.
 
Hi!
Interesting that the same treatment didn't kill the SyncMaster.
Are LCDs susceptible to this problem as well?

Since they aren't coated in the same way that CRTs are, I'd tend to
think the answer is no. However, the topmost layer of the screen is
usually plastic and could melt if the sun got hot enough. I think it
would take hours of very bright direct sunlight before that ever
happened.
Anyone know of any good brands of LCD? I was thinking along
the lines of Samsung, or maybe Sony if someone throws a
huge bag of money my way...

I'm a big fan of the Samsung display panels. I have ones from 15 to 19
inches in size. All of them have been great so far, with good
brightness and sharpness. They are also reasonably priced. Despite
somewhat heavy use, none of them have failed early on and only one was
dead in the box. Samsung replaced it promptly.

The one Viewsonic panel I have puts off a great display. It's not quite
as bright as the Samsung panels, but it works. I also have an AOC
(cheap!) display panel. It is nice looking, and the picture quality is
certainly usable, but the backlighting is not uniform and never has
been.

William
 
P

Philip Pemberton

Jan 1, 1970
0
I'm a big fan of the Samsung display panels. I have ones from 15 to 19
inches in size. All of them have been great so far, with good
brightness and sharpness. They are also reasonably priced. Despite
somewhat heavy use, none of them have failed early on and only one was
dead in the box. Samsung replaced it promptly.

Sounds like Samsung are still making monitors then. Only problem is none of my
regular suppliers stock them :(
The one Viewsonic panel I have puts off a great display. It's not quite
as bright as the Samsung panels, but it works.

I'm not a fan of ultra-bright monitors. Heck, I run my laptop's TFT at minimum
brightness, and the CRT at not much more than 30%.
I also have an AOC
(cheap!) display panel. It is nice looking, and the picture quality is
certainly usable, but the backlighting is not uniform and never has
been.

Like I said, I tend to shy away from the cheapies because they're usually not
much good (and the warranties tend to be along the lines of "send it back to
our factory in Shenzhen and wait four months for a replacement").

Thanks.
 
J

James Sweet

Jan 1, 1970
0
Hi!




Since they aren't coated in the same way that CRTs are, I'd tend to
think the answer is no. However, the topmost layer of the screen is
usually plastic and could melt if the sun got hot enough. I think it
would take hours of very bright direct sunlight before that ever
happened.


I'd be more worried about the color filters in the LCD fading in the
sun, everything else seems to.
 
R

Ron(UK)

Jan 1, 1970
0
Philip said:
Well bugger, that's probably what's done it. The monitor is at a
45-degree angle to a window, and the evening sun usually hits it full-on
(except when I close the curtains, for obvious reasons).

That`s exactly the same as my Diamond Pro 740SB morning sun just clips
the lower corner of the screen, and there is a patch of the coating
missing right there. I must admit though, to one or twice cleaning the
screen with isopropanol

Ron(UK)
 
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