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Purple spot on my Sony KD-34XBR960

post #1 of 31
Thread Starter 
Hello. I bought a Sony KD-34XBR960 from Craigslist last month. I gotta say, I really love the television. It has an excellent sound system and its in HD. My video games, both retro and modern, looks excellent on it.

However recently, I've been noticing a strange purple spot on the upper right side of the screen. Its more noticeable when the background is bright. I've tried unplugging and leaving the TV off for long period, but the purple spot is still there. Does anyone know how to get rid of it? I'm not sure if it was present when the original owner had the TV or if it was caused by slight bumps while we were carrying the TV.
post #2 of 31
Possibly magnetic. If a few power cycles (assuming internal degausser) doesn't resolve it, then...
the shadow mask has been warped. If that's the case, no resolution.

I'd suspect your next question would be, "how do I know if it's the shadow mask"?
IME, just rap/tap on that top/right corner. If the color comes/goes, you're livin' with the purity issue. smile.gif
post #3 of 31
Thread Starter 
I don't think there's anything magnetic near the TV.
post #4 of 31
Is it up in the corner or an island spot? I have a discoloration on a corner of my similar model Panny and improved it with a couple of weak magnets (ferrite pieces from the back of a scrapped CRT) strategically placed on the cabinet about that corner. I did find a crack in the cabinet in that side (it used to be shipped around the country for Kenwood car audio demos).

I'm assuming you didn't re-orient the TV right before this happened since you didn't mention it.

Did you try Ratman's shadow mask test?
post #5 of 31

Sony used Chevrom Magnetts to improve the purity on these CRT's. You will find several already on the CRT by the neck Assembly under the Yoke. Most of the time you can move them or add and clear up your defect. Never use a demagnetizing coil on a Sony CRT... The shadow mask is not concave or convex and thus it will permanently warp it! 

post #6 of 31
Quote:
Originally Posted by t5mustang View Post

Never use a demagnetizing coil on a Sony CRT... The shadow mask is not concave or convex and thus it will permanently warp it! 

No one mentioned an external degaussing coil. Most CRT's had one built in. wink.gif
I'd love to hear more about the concave/convex shadow masks and how a degaussing coil will warp it.
post #7 of 31

I will try to explain the differences in the way Sony Triiton and conventional CRT shadow mask OR  aperture grilles worked and were shipped. This is from a long time ago around the 1980" If my memory recalls. 

Figure one shows the conventional high tension shadow mask that would not easily warp or " artificial" curve. It was designed with a 

Specific tension and a convext or concave appearance depending on your point of view. The reason for the shape and the tension 
Was to defer Doming problems due to thermal expansion of the shadow mask. 
Figure number 2 shows a flat Shadow mask that was used by Sony (later others to include Samsung) is a renewed CRT technology
Resulting in a flat shaped aperture grill (shadow mask). Without the "tension and the dome it  is much more likely to become  
Warped by external forces such as magnification or impact. 
 
 Not wanting to continue, I believe you can find much more information on several web pages than MY memory. 
  
 The only reason I inputted the non  use of an external degaussing coil was for information purposes only. I have witnessed many 
 People do just what I was trying to prevent. 
 
 If I offended someone I apologize. 


 

post #8 of 31
Thread Starter 
Floydage, its only up at the corner and I haven't tried the shadow mask test yet. And what do you mean re-orient?
post #9 of 31
Thanks...
So you're stating that Sony TV's that had an "aperture grill" that was flat(er), and a degausser is bad. How do they make the "built-in" degausser work without causing permanent damage?

Not wanting to continue, I really did look around for something to fortify your statement(s) to no avail. I believe your info should be considered as cautionary, but not to be critically avoided as it sounds. wink.gif

"Damage" is done by people using external degaussers improperly. Also... some love to take off the back of the TV and stick magnets willy-nilly all around. Not a job for a novice. Not only because of making the TV FUBAR, but also because one "OOPS" with a charged cap and it will blow you across the room and leave your kids without a Daddy.biggrin.gif
post #10 of 31
Quote:
Originally Posted by Bracamonte View Post

And what do you mean re-orient?
Did the TV work fine initially when you first brought it home and hooked it up? Trying to determine when/how the problem started. (prior to purchase, during transport, or just cropping up in the home).

Re-orient... move around. NE wall to a SW wall? Large(r) widescreen sets were susceptible to the earth's geomagnetic forces. That's why internal degaussers and tilt controls were implemented.
post #11 of 31
Like he said above, i.e. did you turn the TV a different direction?

On the degausser/aperture grill issue I could see a built-in degausser not causing a problem since it would 'seem' to be positioned along the edge of the grill (vs. someone yanking it running a degauss coil perpendicular to the grill).
I've read other cautionary posts on this forum but I don't recall seeing an article on the subject. confused.gif
post #12 of 31
Quote:
Originally Posted by Floydage View Post

I've read other cautionary posts on this forum but I don't recall seeing an article on the subject. confused.gif
Like "he" said above.

As for reading cautionary posts on this forum, provide a link to help clarify. I don't recall seeing an article on the subject either.
post #13 of 31

127k .pdf file 127k .pdf file Please see the attachment. This may help you as you continue your quest to find a solution. Sorry for the My meter probe is bigger than yours that went on. I just have been involved with consumer electronics for 40 years. This kind of forum can be and you do not know who I am. So that being said. Sony is a special beast when it comes to convergence and purity. If you want the service manual that describes this in more detail I can email it to you. Also, I am sure I can find the training paperwork on the cautionary use of a external degaussing coil. 

post #14 of 31
Thread Starter 
Quote:
Originally Posted by Ratman View Post

Did the TV work fine initially when you first brought it home and hooked it up? Trying to determine when/how the problem started. (prior to purchase, during transport, or just cropping up in the home).

Re-orient... move around. NE wall to a SW wall? Large(r) widescreen sets were susceptible to the earth's geomagnetic forces. That's why internal degaussers and tilt controls were implemented.

Now that you mentioned it, I remember on the second day I had the TV, the purple spot was there, then it went away. How it went away? I don't remember.
post #15 of 31
Quote:
Originally Posted by t5mustang View Post

E26228010-landingadj1.pdf 127k .pdf file E26228010-landingadj1.pdf 127k .pdf file Please see the attachment. This may help you as you continue your quest to find a solution. Sorry for the My meter probe is bigger than yours that went on. I just have been involved with consumer electronics for 40 years. This kind of forum can be and you do not know who I am. So that being said. Sony is a special beast when it comes to convergence and purity. If you want the service manual that describes this in more detail I can email it to you. Also, I am sure I can find the training paperwork on the cautionary use of a external degaussing coil. 
Ha-ha......... okay bud. Yours is bigger than mine. I really don't want to know "who you may be". EMail the manual to the OP. Hope it (or you) will/can help the OP.
Have a good new year! biggrin.gif
Edited by Ratman - 1/9/14 at 1:44pm
post #16 of 31
Ah I see, it says a hand degausser magnetizes the CRT.
post #17 of 31
Yes, when performing that particular procedure.
Why would it state under "Test Equipment Required" a degausser if it shouldn't be used. wink.gif
Perhaps in a later section.
post #18 of 31

Ratman... I was going to let this pass but.. Oh well. I have been an authorized Sony service provider for almost 35 years. I have been in business for 40 years. I worked with the training department and training development at Sony, Pannasonic  and Hitachi.   I worked on the technical advice line for several major consumer electronic companies and I still find time to provide technical point to point 5 step trouble shooting to qualified  electronic technicians. 
  All that being said. I will remove myself from this forum and this conversation, why? Because this is obviously a game to you and to me it is not.

 My advice to the person who asked the question about removing a spot was just that advice. The suggestion to not use a degaussing coil was to prevent him from complicating his situation. I have had many service centers over the years cause damage to the "flat" CRT Tv's and monitors by using a degaussing coil to try and remove spots. IF you have ever tried this on a Sony or other FLAT screen CRT's you would hear an audible rattle of the shadow mask. That rattle is the flat aperture grill rattles and warping. Thus causing an unnatural curve in the FLAT metal surface in turn increasing the Bounce of electrons reflecting in a clear spot visually. 
 The reason I provided him with the bulletin was so he could see that in a Sony trinitron the convergence/purity adjustments are much more complicated than conventional curved screen CRT's. 
What do you pick out? Not the fact that he now is armed with the correct information, but the fact that the provider had the word degaussing coil in the required test equipment. 

I thought the reason for a forum such as this was to provide people with as much information as possible relating to their concerns. NOT to take pop shots at someone you do not agree with. 
 have a nice day and I will leave you with one question.... 
 

 If you read the required equipment list did you happen to notice that one "required " piece of equipment that they left out? 

 

post #19 of 31
Love your resume and appreciate the assistance. But... let's keep it on the level.
1) I never suggested using an external degausser. You made a statement in post #5 to never use one.
2) I asked some questions, some were answered, some were not. Not to worry, I won't lose sleep.
3) no reason to play your pity card

Anyway, I'll back out of this thread and you can assist the OP with a resolution to his issue(s). Should be an easy walkthrough for someone with your experience.

Oh.... and #4: If I answer the question, do I win tickets to the Super Bowl? biggrin.gif
post #20 of 31
Part of what he says is true. If a Trinitron's aperture grille is genuinely warped, it will never be the same again and you might as well pitch it. However, a warped grille is not the same thing as colour purity issues like the OP is having, and you will not necessarily cause a warped grille just by using a deguassing coil. The primary danger that a grille has is in part due to its nature of fine wires as opposed to a slot mask in conventional CRTs. When the television is subjected to stress, it is not impossible that these wires can bunch together. I've even seen stabilizer wires and frames of the grille get dislodged in places, causing a curved, or a "warped" picture, and it's a real shame to see because when it happens typically the rest of the image on the screen is fine. I'll always wonder what happened to the first PVM that I owned, because it had this problem. I continued to use it for years, but the upper right inch-and-a-half or so was always curved.

Anyway, while I suppose that it could happen from degaussing manually, by way of a particular set of wires becoming more or less permanently magnetized, I doubt this was anybody's fear when faced with colour purity problems and the need to degauss in order to fix it. Indeed, the risk of trading one issue (colour purity) for another (warped image) are rather low, and as some colour purity issues do come along with warped screen images, due to the nature of magnetization, you have little to lose by fixing the problem by way of manual degaussing. It is a fix that is not for the faint of heart, and absolutely not a thing to advise a consumer to do without experience if you are working for a company like Sony (they would much rather make a few more bucks by charging for the service anyway), but it is not something that cannot be done safely and properly. See here. Yes, that is a FLAT Trinitron screen. Also works fine on the older, horizontally flat Trinitrons, see the TV on the top.

Edit: I took a closer look at this PDF. It's no surprise they are telling you not to use a hand degausser. "The following adjustments should be made when a complete realignment is required or a new picture tube is installed." The scenario is nothing like the OP's situation and closer to factory setup. Fixing colour purity doesn't require a complete realignment or a new picture tube.
Edited by LiquidSnake - 1/10/14 at 8:42am
post #21 of 31
My take out of all of this is that it's OK to use a degausser for certain procedures, probably at certain minimum distances and at certain locations (ex: perimeter). Better know what the heck you're doing.

What the heck are all those clanking sounds in the first degauss video? eek.gif
post #22 of 31
Quote:
Originally Posted by Bracamonte View Post

Now that you mentioned it, I remember on the second day I had the TV, the purple spot was there, then it went away. How it went away? I don't remember.

That leads me to believe the internal degausser resolved the spot after you turned it on once or more; the original spot was probably a result of the TV's new compass location. It's possible now that degausser is no longer operating (I had the degausser circuit fry on an old CRT). Does it still make the familiar boing sound when you turn on the TV after it's been off for 15 minutes or so?
post #23 of 31
Thread Starter 
Quote:
Originally Posted by Floydage View Post

That leads me to believe the internal degausser resolved the spot after you turned it on once or more; the original spot was probably a result of the TV's new compass location. It's possible now that degausser is no longer operating (I had the degausser circuit fry on an old CRT). Does it still make the familiar boing sound when you turn on the TV after it's been off for 15 minutes or so?

Yes, the TV still does the humming sound when it turns on. So what am I supposed to do, rotate it?
post #24 of 31
Quote:
Originally Posted by Bracamonte View Post

Yes, the TV still does the humming sound when it turns on. So what am I supposed to do, rotate it?

"Humming" is throwing me off since CRT's tend to hum while on. I'm referring to what sounds kinda like a spring action (the degauss coil is dampened with springs). Anyhow if it makes that kind of sound for just a few seconds than it's working. If that's the case than refer to my post #4. I suspect you don't have any ferrite pieces so play with some really weak magnets like small sheet refrigerator magnets. I was able to 'tune' mine the best with a white screen; fortunately for you it's winter so a ski competition or the like should be easy to find. biggrin.gif
post #25 of 31
Thread Starter 
Quote:
Originally Posted by Floydage View Post

"Humming" is throwing me off since CRT's tend to hum while on. I'm referring to what sounds kinda like a spring action (the degauss coil is dampened with springs). Anyhow if it makes that kind of sound for just a few seconds than it's working. If that's the case than refer to my post #4. I suspect you don't have any ferrite pieces so play with some really weak magnets like small sheet refrigerator magnets. I was able to 'tune' mine the best with a white screen; fortunately for you it's winter so a ski competition or the like should be easy to find. biggrin.gif

Yes I know what you're talking about. It does make the spring noise after I leave it off for while. And the small magnets won't cause any damage to the screen or permanent spots? Just curious.

And according to your #4 post, in my case, there are no signs of any physical cracks or dents on the side of the TV.

Update 1/12: Unless my mind is playing tricks, I am noticing the purple spot has faded a bit. Its still there, but not as noticeable as before.
Edited by Bracamonte - 1/12/14 at 11:13am
post #26 of 31
Quote:
Originally Posted by Bracamonte View Post

Update 1/12: Unless my mind is playing tricks, I am noticing the purple spot has faded a bit. Its still there, but not as noticeable as before.

From post #2:
"Possibly magnetic. If a few power cycles (assuming internal degausser) doesn't resolve it, then..."

Perhaps with a few more power cycles, the internal degausser will resolve the issue completely.
post #27 of 31
Keep up the good work. smile.gif Assuming you had already cycled it several times, maybe the internal degauss coil slipped off that corner a bit from the bumping.
post #28 of 31
Thread Starter 
Thanks, I've also used a small refrigerator magnet to help.

A little bit off-topic, but does anyone know any good stereo speakers for this TV?
post #29 of 31
Get powered external speakers that are magnetically shielded.
post #30 of 31
Thread Starter 
Quote:
Originally Posted by Ratman View Post

Get powered external speakers that are magnetically shielded.

Do you know any speakers like those?
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