My Sony TV is discolored in the upper corners

December 21, 2004 8:03 AM

My TV is discolored in the upper corners -- reddish on the right, and greenish on the left. It looks like typical magnet damage, and it's especially apparent on a solid blue picture. Is there a way to fix this? [MI]

The TV is a 27" Sony Wega and it's three years old. I have speakers on the floor on either side of it, but the woofers are at floor level while the TV is up about 3 feet. I don't see why my speakers would have caused it. One person suggested that the built-in TV speakers on the sides can do it. However, wouldn't Sony have shielded their speakers?

posted by knave to technology (15 comments total)

Degauss...
posted by weston at 8:07 AM on December 21, 2004

Here's an option for a home-brew approach to degaussing that's a little less scary than weston's link...

(You're still probably better off getting a legit degaussing device from a Radio Shack or service shop, if they're not too expensive.)
posted by LairBob at 8:13 AM on December 21, 2004

If you're certain that it's not your speakers that are causing the problem (easy enough to check by moving them away temporarily) it's worth checking that there are no other magnets or large metal objects nearby. I had a similar problem a few years ago which was caused by the TV being positioned too close to a radiator.
posted by Nick Jordan at 8:15 AM on December 21, 2004

Knave: I did just what LairBob suggests, thanks in large part to the kindness of mimi, who lent me some hella powerful magnets.

Results:

At first, I saw no progress, and was sure I was just making it worse. I did everything suggested -- magnets on a drill moving in an ever-expanding spiral parallel to the screen, followed by moving backward away from the screen -- and while I definitely got a reaction, it didn't look fixed. It looked worse. A half hour later, though, I thought it looked better than before, although I lacked a good reference blue screen to see if it was really perfect. I've started to pick up some of the imperfections again, so I'm guessing it didn't "take" perfectly. Your local TV repair guy will have a big degaussing coil that he'll bring to your place and provide a similar, if likely better, service. That may be easier and more cost/time-effective than finding sufficiently strong magnets, frankly.
posted by blueshammer at 8:26 AM on December 21, 2004

Some TVs have an auto-degauss when powered on and off rapidly in succesion. Try that, it has worked for me in the past...
posted by SNACKeR at 8:54 AM on December 21, 2004

Another option. Grab a computer monitor (they usually have a degauss option in the onscreen menu). Take said monitor, hold it up so that it's screen is almost touching the affected screen. Fire up the degauss on the monitor. The magnetic field should be plenty to also degauss the TV. I've never tried it with something that big (27") though.
posted by defcom1 at 9:14 AM on December 21, 2004

I believe a WEGA (and most decent quality CRTs) will degauss itself using built-in coils if you unplug it for 20 minutes, plug it in again, and turn it on. Even my fair-to-middling JVC 31" from 8 years ago had this feature.
posted by majick at 10:28 AM on December 21, 2004

(And the feature worked when a 2 year old mauled the TV with a magnet)
posted by majick at 10:28 AM on December 21, 2004

I have the same TV....and the same problem. While the TV has self-degaussing, it doesn't seem to work. I was planning on eventually getting a degaussing coil and hope that works, however my annoyance-to-laziness ratio hasn't flipped over yet.
posted by jawbreaker at 10:35 AM on December 21, 2004

The discoloration has been building for at least 1 year now. I know it's been unplugged for more than 20 minutes several times and it has never fixed itself. The built-in degausser must not be strong enough.

Thanks for the do-it-yourself degaussing instructions, I may try that if I'm brave enough! :)

jawbreaker, that makes me think this is definitely a design flaw -- unshielded speakers, maybe. For such an expensive device, it's really aggravating.
posted by knave at 11:06 AM on December 21, 2004

Same TV, same problem. Thanks, AskMe!
posted by grateful at 11:10 AM on December 21, 2004

I have the same problem with a 35" Sony. I did some research on this and found it's a common problem with Sony TVs. These TVs all have an automatic degaussing circuit that kicks in during power-on. It sounds like a low-pitched "thunnnnnnnnnnnnngggg" for a second or two during power up before the CRT turns on. The problem is there is often a cold solder joint somewhere on the degassing coil that prevents it from working. On my TV, if I turn it on cold all I hear is a click and it will usually have blue discoloration in one of the corners. If I wait about 10 minutes and then power-cycle it (via remote is fine, no need to unplug), I can get the degaussing circuit to kick in and it clears up the picture. Supposedly a technician can fix this in a few minutes by resoldering the cold solder joint, but I've never had it taken care of.
posted by AstroGuy at 12:41 PM on December 21, 2004

There are some hacks available, accessed through the remote.
posted by five fresh fish at 2:02 PM on December 21, 2004

OK, I'll bite, fff--any hints?
posted by LairBob at 3:55 PM on December 21, 2004

You're probably SOL; your convergence is shot.
posted by joeclark at 3:21 PM on December 27, 2004