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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Red face magnet on tv screen

i might be on a loser here but does anybody know if you can fix a tv screen after a magnet has been held against it(my 4 year old daughter) it is a sony 28" crt widescreen tv. there is discolour in one corner where the magnet has actually touched the screen.
if not the tv is a rental anyway so i will have to return it a play dumb about the problem.
any help would be great
thanks
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Default magnet on tv screen

david wilson writes:

i might be on a loser here but does anybody know if you can fix a tv
screen after a magnet has been held against it(my 4 year old daughter)
it is a sony 28" crt widescreen tv. there is discolour in one corner
where the magnet has actually touched the screen.
if not the tv is a rental anyway so i will have to return it a play
dumb about the problem.
any help would be great


Unless it was a really powerful manget, should clear up in a few
days or after a few power cycles (on 5 minutes, off 15 minutes, repeat).
The degauser will do its job.

--- 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

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Default magnet on tv screen


"david wilson" wrote in message
...

i might be on a loser here but does anybody know if you can fix a tv
screen after a magnet has been held against it(my 4 year old daughter)
it is a sony 28" crt widescreen tv. there is discolour in one corner
where the magnet has actually touched the screen.
if not the tv is a rental anyway so i will have to return it a play
dumb about the problem.


Leave it be. It will fix itself.




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Default magnet on tv screen

david wilson wrote:
i might be on a loser here but does anybody know if you can fix a tv
screen after a magnet has been held against it(my 4 year old daughter)
it is a sony 28" crt widescreen tv. there is discolour in one corner
where the magnet has actually touched the screen.
if not the tv is a rental anyway so i will have to return it a play
dumb about the problem.
any help would be great
thanks




You can build a degausser. Wrap an iron rod with wire. Then run an ac
current through it and wave it over the magnatized area on the screen.

--

Attention Please:
All those who have 2, turn one in.
All those who are without, draw 1.
Thank you very much.

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Default magnet on tv screen

If the mask in the CRT is not damaged, this will probably clear in a number
of days, from the degasser cycling every time the set is powered off and on
again.

The other way to clear this, is to have a hand held CRT degaussing coil, and
demagnetize the screen.

--

JANA
_____


"david wilson" wrote in message
...

i might be on a loser here but does anybody know if you can fix a tv
screen after a magnet has been held against it(my 4 year old daughter)
it is a sony 28" crt widescreen tv. there is discolour in one corner
where the magnet has actually touched the screen.
if not the tv is a rental anyway so i will have to return it a play
dumb about the problem.
any help would be great
thanks




--
david wilson




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Default magnet on tv screen

Claude writes:

david wilson wrote:
i might be on a loser here but does anybody know if you can fix a tv
screen after a magnet has been held against it(my 4 year old daughter)
it is a sony 28" crt widescreen tv. there is discolour in one corner
where the magnet has actually touched the screen.
if not the tv is a rental anyway so i will have to return it a play
dumb about the problem.
any help would be great
thanks


You can build a degausser. Wrap an iron rod with wire. Then run an ac
current through it and wave it over the magnatized area on the screen.


There should be no need to do this. The internal degausser should clear
it up in a few days or sooner.

--- 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.
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Default magnet on tv screen



david wilson wrote:

i might be on a loser here but does anybody know if you can fix a tv
screen after a magnet has been held against it(my 4 year old daughter)
it is a sony 28" crt widescreen tv. there is discolour in one corner
where the magnet has actually touched the screen.
if not the tv is a rental anyway so i will have to return it a play
dumb about the problem.
any help would be great


If it doesn't clear up on its own ( I have known this happen with computer
monitors ) the use of a hand-held degausser would fix it ( eg by a repair chap
).

Certainly nothing serious to worry about.

Graham

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Default magnet on tv screen

Claude wrote:

You can build a degausser. Wrap an iron rod with wire. Then run an ac
current through it and wave it over the magnatized area on the screen.



That's a good way to warp the shadow mask. You want the alternating
magnetic field spread out over a larger area. I made 14" diameter coils
with 250 turns of 17 AWG double enamel with a double cotton covered
wire. I made a coil winder and wound a bunch of them in 1970. I also
used a heavy duty push button switch and a 20 foot AC cord so it was
easier to find an outlet to use it on service calls. I still have the
first one I built.



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prove it.
Member of DAV #85.

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Central Florida
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Default magnet on tv screen

Try unplugging the TV overnight. After about 30mins most TVs will
automatically Degauss when reconnected. Standby is not enough. Might
need a few attempts.

Wilfred


david wilson wrote:
i might be on a loser here but does anybody know if you can fix a tv
screen after a magnet has been held against it(my 4 year old daughter)
it is a sony 28" crt widescreen tv. there is discolour in one corner
where the magnet has actually touched the screen.
if not the tv is a rental anyway so i will have to return it a play
dumb about the problem.
any help would be great
thanks




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Default magnet on tv screen

On Wed, 29 Nov 2006 08:58:35 +0000, Wilfred wrote:

david wilson wrote:
i might be on a loser here but does anybody know if you can fix a tv
screen after a magnet has been held against it(my 4 year old daughter)
it is a sony 28" crt widescreen tv. there is discolour in one corner
where the magnet has actually touched the screen.
if not the tv is a rental anyway so i will have to return it a play
dumb about the problem.
any help would be great
thanks


Try unplugging the TV overnight. After about 30mins most TVs will
automatically Degauss when reconnected. Standby is not enough. Might
need a few attempts.


And if that doesn't shift the coloured spot, you can use the magnet again
to neutralize the magnetization. Simply pass the magnet over the
discolouration with a semi-circular/wiping motion at 1 centimeter from
the screen at the closest point, making sure the magnet always travels
over the spot in the same direction, and with the same orientation
(North/South).
If the discolouration gets worse instead of better, flip the magnet over,
so the opposite pole points to the screen. If all goes well, most of the
discolouration should be gone after about half a dozen passes. The
degaussing function (as described by Wilfred) should get rid of whatever
is left.


Richard Rasker

--
Linetec Translation and Technology Services

http://www.linetec.nl/



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Default magnet on tv screen

On Wed, 29 Nov 2006 08:58:35 GMT, Wilfred wrote:


Try unplugging the TV overnight. After about 30mins most TVs will
automatically Degauss when reconnected. Standby is not enough. Might
need a few attempts.


You should refrain from giving advice you've never tried.
The degaussing coil of a TV isn't strong enough to undo the damage from
a hand magnet. Maybe if you unplug the set and plug it in again forty
or fifty times, it might start to erase the magnetized spot.

You need something with a stronger AC field. Back in the days of tape
cassettes, bulk tape erases worked well. A largish AC adapter (stuck into
an extension cord for portability) might generate enough of a field. Maybe
a AC powered shaver would have a strong enough field?
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Default magnet on tv screen

On Wed, 29 Nov 2006 11:02:00 +0100, Richard Rasker wrote:


On Wed, 29 Nov 2006 08:58:35 +0000, Wilfred wrote:


david wilson wrote:
i might be on a loser here but does anybody know if you can fix a tv
screen after a magnet has been held against it(my 4 year old daughter)
it is a sony 28" crt widescreen tv. there is discolour in one corner
where the magnet has actually touched the screen.
if not the tv is a rental anyway so i will have to return it a play
dumb about the problem.
any help would be great
thanks


Try unplugging the TV overnight. After about 30mins most TVs will
automatically Degauss when reconnected. Standby is not enough. Might
need a few attempts.


And if that doesn't shift the coloured spot, you can use the magnet again
to neutralize the magnetization. Simply pass the magnet over the
discolouration with a semi-circular/wiping motion at 1 centimeter from
the screen at the closest point, making sure the magnet always travels
over the spot in the same direction, and with the same orientation
(North/South).
If the discolouration gets worse instead of better, flip the magnet over,
so the opposite pole points to the screen. If all goes well, most of the
discolouration should be gone after about half a dozen passes. The
degaussing function (as described by Wilfred) should get rid of whatever
is left.


Also: step back slowly while waving the magnet around. I've successfully
removed magnetized spots with that technique.

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Default magnet on tv screen

AZ Nomad wrote:
On Wed, 29 Nov 2006 08:58:35 GMT, Wilfred wrote:


Try unplugging the TV overnight. After about 30mins most TVs will
automatically Degauss when reconnected. Standby is not enough. Might
need a few attempts.


You should refrain from giving advice you've never tried.
The degaussing coil of a TV isn't strong enough to undo the damage from
a hand magnet. Maybe if you unplug the set and plug it in again forty
or fifty times, it might start to erase the magnetized spot.

You need something with a stronger AC field. Back in the days of tape
cassettes, bulk tape erases worked well. A largish AC adapter (stuck into
an extension cord for portability) might generate enough of a field. Maybe
a AC powered shaver would have a strong enough field?


Hi...

In the absence of a degausser or bulk eraser, a soldering gun
will do the job, albeit slowly.

Take care.

Ken





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Default magnet on tv screen

AZ Nomad wrote:
On Wed, 29 Nov 2006 08:58:35 GMT, Wilfred wrote:


Try unplugging the TV overnight. After about 30mins most TVs will
automatically Degauss when reconnected. Standby is not enough. Might
need a few attempts.


You should refrain from giving advice you've never tried.
The degaussing coil of a TV isn't strong enough to undo the damage from
a hand magnet. Maybe if you unplug the set and plug it in again forty
or fifty times, it might start to erase the magnetized spot.

You need something with a stronger AC field. Back in the days of tape
cassettes, bulk tape erases worked well. A largish AC adapter (stuck into
an extension cord for portability) might generate enough of a field. Maybe
a AC powered shaver would have a strong enough field?

Yes, Perhaps I should declare my only experience with this subject is
with a speaker I put too close to the TV. What I suggested did work for
me. A hand magnet on the screen might be an entirely different story.

Still , my suggestion wouldn't have done any harm either, and it "might"
have worked.

Wilfred
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Default magnet on tv screen


"AZ Nomad" wrote in message
...

You need something with a stronger AC field. Back in the days of tape
cassettes, bulk tape erases worked well. A largish AC adapter (stuck into
an extension cord for portability) might generate enough of a field.
Maybe
a AC powered shaver would have a strong enough field?


VHS tape eraser.





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Default magnet on tv screen



Homer J Simpson wrote:

"AZ Nomad" wrote in message
...

You need something with a stronger AC field. Back in the days of tape
cassettes, bulk tape erases worked well. A largish AC adapter (stuck into
an extension cord for portability) might generate enough of a field.
Maybe
a AC powered shaver would have a strong enough field?


VHS tape eraser.


I have a tape head demagnetiser that's good for this.

Graham


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Default magnet on tv screen

AZ Nomad wrote:
On Wed, 29 Nov 2006 08:58:35 GMT, Wilfred wrote:


Try unplugging the TV overnight. After about 30mins most TVs will
automatically Degauss when reconnected. Standby is not enough. Might
need a few attempts.


You should refrain from giving advice you've never tried.
The degaussing coil of a TV isn't strong enough to undo the damage from
a hand magnet. Maybe if you unplug the set and plug it in again forty
or fifty times, it might start to erase the magnetized spot.

You need something with a stronger AC field. Back in the days of tape
cassettes, bulk tape erases worked well. A largish AC adapter (stuck into
an extension cord for portability) might generate enough of a field. Maybe
a AC powered shaver would have a strong enough field?


You appear to have forgotten your own advice. transformers dont produce
enough field, nor do shavers or motors, I've tried both on floppy
discs, with no effect. A shadowmask is a distance away from the front
of the screen, so will see even less field strength. Once you see a
bulk eraser you'll see why motors etc wont do it.


NT

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Default magnet on tv screen

AZ Nomad wrote:
On Wed, 29 Nov 2006 08:58:35 GMT, Wilfred wrote:


Try unplugging the TV overnight. After about 30mins most TVs will
automatically Degauss when reconnected. Standby is not enough. Might
need a few attempts.


You should refrain from giving advice you've never tried.
The degaussing coil of a TV isn't strong enough to undo the damage from
a hand magnet. Maybe if you unplug the set and plug it in again forty
or fifty times, it might start to erase the magnetized spot.

You need something with a stronger AC field. Back in the days of tape
cassettes, bulk tape erases worked well. A largish AC adapter (stuck into
an extension cord for portability) might generate enough of a field. Maybe
a AC powered shaver would have a strong enough field?


You appear to have forgotten your own advice. transformers dont produce
enough field, nor do shavers or motors, I've tried both on floppy
discs, with no effect. A shadowmask is a distance away from the front
of the screen, so will see even less field strength. Once you see a
bulk eraser you'll see why motors etc wont do it.

Tape head demagger also had no effect.


NT

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