Degauss TV screen

J

JRRR

Jan 1, 1970
0
A magnet was swiped across my TV screen, leaving a purplish swath. Is
there a way to fix this problem?
 
D

DaveM

Jan 1, 1970
0
JRRR said:
A magnet was swiped across my TV screen, leaving a purplish swath. Is
there a way to fix this problem?

Yes, there is a tool called a "Degaussing Coil" (imagine that!!!). You can buy
one from online vendors
http://www.mcminone.com/product.asp?catalog_name=MCMProducts&product_id=72-785
http://www.elexp.com/cpt_1dgc.htm

Other vendors might also stock them... Google for "degaussing coil"

--
Dave M
MasonDG44 at comcast dot net (Just substitute the appropriate characters in the
address)

Some days you're the dog, some days the hydrant.
 
H

Homer J Simpson

Jan 1, 1970
0
A magnet was swiped across my TV screen, leaving a purplish swath. Is
there a way to fix this problem?

Leave it be. It will fix itself. Unless you know what you are doing you may
make it worse.

If you do know what you are doing try a video tape degausser with the usual
precautions.
 
I

Impmon

Jan 1, 1970
0
Yes, there is a tool called a "Degaussing Coil" (imagine that!!!). You can buy
one from online vendors
http://www.mcminone.com/product.asp?catalog_name=MCMProducts&product_id=72-785
http://www.elexp.com/cpt_1dgc.htm

Other vendors might also stock them... Google for "degaussing coil"

I have a set of coils salvaged from a monitor. It was wired for
direct 110v operation via a thermal resistor to shut it off after
initial power up and degaussing. Can I just wire a standard 110v plug
with a N.O. push button switch instead to zap anything that needs
clearing up?
 
J

JRRR

Jan 1, 1970
0
Homer said:
Leave it be. It will fix itself. Unless you know what you are doing you may
make it worse.

If you do know what you are doing try a video tape degausser with the usual
precautions.

Dho! It fixed itself. Thanks everybody! Let's all get degaussed!
 
J

jasen

Jan 1, 1970
0
A magnet was swiped across my TV screen, leaving a purplish swath. Is
there a way to fix this problem?

you can try to erase it using the same magnet reversed, this won't be
perfect,

or give it a few weeks, it'll fade gradually.

Or if you're in a hurry you can erase the mark using an ac powered
electromagnet.

Or take it to a TV repairman, it's a 2 minute job.

Bye.
Jasen
 
J

jasen

Jan 1, 1970
0
I have a set of coils salvaged from a monitor. It was wired for
direct 110v operation via a thermal resistor to shut it off after
initial power up and degaussing. Can I just wire a standard 110v plug
with a N.O. push button switch instead to zap anything that needs
clearing up?

If you have 110V (ish) AC, then yes.
if it gets hot let it cool down.

Bye.
Jasen
 
A

Art

Jan 1, 1970
0
Depending on what type of set you have, a lot of new SONY televisions can
be permantly damaged by using a degaussing coil on the crt. The aperture
grill assembly can be dislodged or damaged within the crt rendering it
useless and requiring a new crt to be installed. Since you did not post make
and model number of the set this is sent for informational purposes only.
 
S

sundar

Jan 1, 1970
0
JRRR said:
Dho! It fixed itself. Thanks everybody! Let's all get degaussed!

Can anyone here explain how it did this? That is, how did a TV affected
by a magnetic field clear itself without any outside help?
 
H

Homer J Simpson

Jan 1, 1970
0
sundar said:
Can anyone here explain how it did this? That is, how did a TV affected
by a magnetic field clear itself without any outside help?

All color TVs have a circuit to do this which runs once when you switch on.
If the magnetization is severe it may take a few times.
 
S

scada

Jan 1, 1970
0
JRRR said:
A magnet was swiped across my TV screen, leaving a purplish swath. Is
there a way to fix this problem?

All crt tv's have a built in degaussing circuit. They use a PTC (positive
temperature coefficient) resistor to limit the current through the
degaussing coil. Therefore when the TV is first turned on, the coil sees a
large current, as the PTC heats up the current decreases (resistance
increases) until it reaches a very low current that won't affect the CRT
deflection. When the set is turned off, the PTC cools down, lowering it's
internal resistance for the next TV turn on. If you just cycle the set
normally eventually it should correct itself.
 
J

jasen

Jan 1, 1970
0
Can anyone here explain how it did this? That is, how did a TV affected
by a magnetic field clear itself without any outside help?

They use a type of steel that doesn't retain magnetism well,
there is also a degaussing coil attached behind the screen
(it's what makes the "fong" sound when you turn the set on)
 
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