Your Universal Remote Control Center
RemoteCentral.com
Custom Installers' Lounge Forum - View Post
Previous section Next section Previous page Next page Up level
Up level
The following page was printed from RemoteCentral.com:

Login:
Pass:
 
 

Page 1 of 2
Topic:
TV Problems
This thread has 17 replies. Displaying posts 1 through 15.
Post 1 made on Wednesday January 15, 2003 at 20:18
McNasty
Founding Member
Joined:
Posts:
January 2002
1,322
Hi everyone, I've got a problem. I have a 32" Panasonic TV that I bought baout 5 years ago and it seems like its going on me. It all started about a year ago when I noticed that two 10" woofers were in a closet on the opposite side of the wall my TV was against and it caused the screen to get that wonderful rainbow effect that magnets like to cause. Well, I moved the TV and ever since it was VERY sensitive to magnetism. To the point that my DVD player effects it and I had to keep it at least a foot away. But, the problem I am having is that I get Green, Purple, and faded color splotches very sparaticly. I don't get it...Is it dying on me? Or is there something I can do. I was hoping it would last me until I could afford a plasma, but I don't see that happening. I just don't wanna settle for somthing other than HD as a replacement and I don't think I can afford that right now. So if there is something that can be done to fix the sensitivity then I would rather go that route. Any help would be GREAT!
Post 2 made on Wednesday January 15, 2003 at 21:36
avdude
Founding Member
Joined:
Posts:
February 2002
814
McNasty,

Try a degausser, or maybe even a large magnetic tape eraser from Radio Shack. Many time, when a CRT is magnetized, it does VERY funky things until it's COMPLETELY degaussed.

Other questions would be:

Do you have a tape deck, PVR or TIVO anywhere near your TV?

Is it in or near any brick or natural rock (like an inset next to a fireplcae or the like)?

I've seen all these things cause weirdness....

Brian
AVDUDE
"It might work better if it were plugged in and programmed first...just a thought!"
Post 3 made on Wednesday January 15, 2003 at 22:44
Larry Fine
Loyal Member
Joined:
Posts:
August 2001
5,002
All color TVs have built-in deGaussing. Each time you turn on the TV, a little bit of demagnetizing of the shadow mask (perforated steel plate) is done. It's not as strong as an external coil, so it takes many cycles to eliminate a strong magnetization.

The circuit uses thermistors, which pass current when cool, and resistance increases as the set warms up. In other words, you can't just turn the set on and off a bunch of times in a short period. Maybe once every 20 minutes, or over several weeks of normal use.

The other option is to find a deGaussing coil either from an electronics supplier, or see if a local TV repair shop will lend you one, or not charge too much to do it. Bringing the set to them will cost less, but it's better if the TV isn't moved after it's done.

If you do it yourself, you'll need to hold the coil flat with the face of the screen, a few inches away, and move the coil in a circular motion around the circumference of the screen. One word of caution: it's important to switch the coil off only after moving it many feet away from the TV, or you'll remagnetize the shadow mask with a new pattern.

Here's the results of a Metacrawler search about deGaussing.

Larry
www.fineelectricco.com
Post 4 made on Thursday January 16, 2003 at 19:11
natasrof1
Long Time Member
Joined:
Posts:
January 2003
69
I had the same problem on a brand new 32" panasonic out of the box and I called Panasonic and asked WTF was I going to have to take it back to get it degaussed and they said no, just turn it off and on a few times and it will go away. I thought that was BS untill I did it and it went away. This was light magnatisim I do not know if it would work if It was more severe.
OP | Post 5 made on Friday January 17, 2003 at 07:15
McNasty
Founding Member
Joined:
Posts:
January 2002
1,322
Thanks for all the info guys. I'll probably have it degaussed and see if that helps. I have tried the ob/off tactics in the pat, and he tried un plugging and plugging back in (For some reason that works well with Sony Wegas) But none of it helps with this. It is so weird. I've never seen a TV do it as random as this one. I thought it was just starting to burn out because when I first turn it on the colors have a lot of bleeding for the first 15-20 seconds.
Post 6 made on Saturday January 18, 2003 at 02:59
Tom Ciaramitaro
Loyal Member
Joined:
Posts:
May 2002
7,958
The built in degaussers in TVs and computer monitors work fine but are only a fraction as strong as a TV man's outboard degausser.

Bringing speakers too close that are not shielded, or the wife running the vacuum cleaner too close can leave magnetism that will distort the path of the electron beam(s) and cause 'splotches'.

Once in awhile the tube will have a defect where taping small magnets to the back of the tube are needed to get the remaining bad spots out. Manufacturers will touch up the set this way occasionally when they are about to leave the factory.

BTW, the best way to see whether you have a problem with this (called 'color purity') is to set your DVD or receiver's onscreen menu background to RED. The red gun shows purity problems better than the green or blue. Trying to determine if the purity is good with moving video is pretty tough.

Larry's comment about turning it off is good. Just like in the days of demagnetizing tape heads on the cassette or reel to reel: Turn it on away from the unit, bring it slowly in, then slowly out with a circular motion. Only when you are a good distance away should you shut the thing off. You can have the set running when you do this - the colors reproduced can keep the kids out of trouble for a couple minutes!
There is no truth anymore. Only assertions. The internet world has no interest in truth, only vindication for preconceived assumptions.
Post 7 made on Saturday January 18, 2003 at 10:18
Matt
Founding Member
Joined:
Posts:
August 2001
1,802
I recommend turning the coil 90 degrees before you turn it off...
Post 8 made on Saturday January 18, 2003 at 17:44
Ernie Bornn-Gilman
Yes, That Ernie!
Joined:
Posts:
December 2001
30,104
Yeah, the whole thing with getting the coil away before turning it off is to be sure that you don't remagnetize it.

If you have the coil anywhere near the TV when you plug it in or unplug it (plug it out?) (English!), and you happen to make the electrical connection at a portion of the electrical cycle where there is lots of voltage, there will be a burst of magnetism. This is obviously worse on shutting off the coil, because you expect to be demagnetized at that point. The degausser takes advantage of the constant repetitive reversals of voltage polarity and thus magnetic polarity; when you slowly move this reversing field away from the tube, it magnetizes in one direction, then demagnetizes and remagnetizes a bit less in the other direction, etc so the magnetization becomes less and less as you move away. Then you unplug it and BAM! you can get a magnetic pulse a lot larger than the ones you get when it is plugged in.

Thus turning it 90 degrees helps, too, as noted, because that directs the magnetic field away from the tube.
A good answer is easier with a clear question giving the make and model of everything.
"The biggest problem in communication is the illusion that it has taken place." -- G. “Bernie” Shaw
Post 9 made on Saturday January 18, 2003 at 23:14
phil
Founding Member
Joined:
Posts:
December 2001
2,164
Some of the newer Sony CRTs can be damaged if you use an outboard degausser.
"Regarding surround sound, I know musicians too well to want them behind my back."
-Walter Becker
Post 10 made on Sunday January 19, 2003 at 23:39
cramstad
Long Time Member
Joined:
Posts:
December 2002
41
On 01/18/03 23:14, phil said...
Some of the newer Sony CRTs can be damaged if
you use an outboard degausser.

Really? Why?
Post 11 made on Monday January 20, 2003 at 16:34
phil
Founding Member
Joined:
Posts:
December 2001
2,164
At the Sony service training a couple of years ago they said that in manufacturing their larger sets some small permanent magnets are installed in specific locations in the crt dependent on what part of the country the set is going to. A manual degausser is strong enough to demagnetize these, the built in degausser is not. The impression I got was that these are part of the CRT and not replaceable.
"Regarding surround sound, I know musicians too well to want them behind my back."
-Walter Becker
Post 12 made on Monday January 20, 2003 at 23:26
avdude
Founding Member
Joined:
Posts:
February 2002
814
That would definitley explain a lot of things with Sony TV's, they're shipping them to the wrong parts of the country!! HAH!!
AVDUDE
"It might work better if it were plugged in and programmed first...just a thought!"
Post 13 made on Tuesday January 21, 2003 at 10:59
JJ Bugsy
Long Time Member
Joined:
Posts:
January 2003
118
Phil,
Those little magnets Sony attaches to the back of their large CRTs, are solely to compensate for the Earth magnetic fields, wich vary in different parts of the surface of the Earth, not for degaussing purposes.
Post 14 made on Tuesday January 21, 2003 at 22:24
Mister. T
Long Time Member
Joined:
Posts:
January 2003
270
McNasty, did you solve your problem yet ? If you didn't let me know I have the fix for you,
Mister. T
OP | Post 15 made on Wednesday January 22, 2003 at 07:31
McNasty
Founding Member
Joined:
Posts:
January 2002
1,322
No, I haven't, but only because I haven't had the time to mess with it yet. I've been working on a prewire in this FREEZING weather on a house that isn't weather tight yet. All I wanna do when I get home is warm up and lay down.
Page 1 of 2


Jump to


Protected Feature Before you can reply to a message...
You must first register for a Remote Central user account - it's fast and free! Or, if you already have an account, please login now.

Please read the following: Unsolicited commercial advertisements are absolutely not permitted on this forum. Other private buy & sell messages should be posted to our Marketplace. For information on how to advertise your service or product click here. Remote Central reserves the right to remove or modify any post that is deemed inappropriate.

Hosting Services by ipHouse