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Discussion Starter · #1 ·
Yesterday I was watching a couple of movies on my Sony 1292. Early into the second one, I noticed a faint, thin, white horizontal line above the image.


The line is there regardless of what the projector is showing - no input, computer input (4:3 and 16:9 settings) and with the internal test pattern.


Blanking has no effect on it and neither does RGB shift. RGB size moves it, in that it always stays slightly above the active image.


Turned the pj on briefly today in the vain hope that it had disappeared; of course it hasn't.


Haven't got a digital camera, so can't readily make a photo of it, but hope the description below will suffice:


When looking through the lenses, with no input, what I see is the following: A large, very faint, slightly trapezodial square, corresponding to the active image. (Raster ?). A little below it is a bright, straight horizontal line, reaching all across the tube face (and thus wider than the large square). Between this line and the square is another line, very faint (same intensity as the square). It is attached to the straight, bright line at the ends, and curves up towards the square, but does not quite reach it in the middle. This line is too faint to be visible on the screen. The pattern is identical for all three tubes. Pj is ceiling mounted btw.


Besides being annoying in dark scenes, I'm worried that it will burn itself into the tubes although being faint. Assuming it's there to stay, it will remain in the same two positions for 16:9 and 4:3 respectively.


It's the thing that leaves you scratching your head, wondering if it has been there all along, but I've used the pj intensely since mounting it early this January, and I can't imagine I wouldn't have noticed it before, as it's quite conspicuous during dark scenes.


Anyone have any ideas ? Have I just been blind for not noticing it before, or is a problem that can arise - and hopefully be solved ?


Thanks in advance,


Erling,

Worried CRT father...
 

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Don't worry, it's meant to be there. It is the AKB, or Automatic White balance. You can turn it off, but are then up for a lot of calibration work. Try turning it off in the menu and you'll see what I mean.
 

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Discussion Starter · #3 ·
Thanks for the reply, it does sound reassuring.


I'm just surprised that I could overlook it, if it's been there all along.


Will try and see if I can figure out how to turn it off, like you suggest, once I turn on the pj later tonight.
 

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Discussion Starter · #4 ·
Have had a look now, but can't find anything about automatic white balance in the menus on the projector.


Have looked in the setup manual too. It has a section about adjusting white balance, using BIAS and GAIN controls. It doesn't mention automatic white balance or how to turn it off.


Pete, are you certain that the 1292 has automatic white balance ?


Anyone else with 1292s - do you see the same line as me ?


Again thanks in advance for any replies.
 

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I used to have a 1271QM and the AKB line was there too.

On that unit I had to set a jumper inside the projector to disable it. Don't know about the 1292 though.


My advice is not to worry about it as it's supposed to be there. The projector is measuring the wear on the tubes.


Kjell
 

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Discussion Starter · #7 ·
Thanks all for the replies.


Have looked for AKB in the manual again, but so far not found anything. There's no index, so I more or less have to plough through the text. It's the service manual btw. - not the setup manual, my mistake.


Is there any plausible explanation as to why this line suddenly becomes visible ?

I'm about ready to swear on my mother's grave that it wasn't there two days ago. I haven't changed any settings, at least not deliberately.

I'm using Theatertek for DVD playback and whenever there's no DVD in the drive, all that was visible on screen before was the Theatertek logo on a completely black background. Now I have the logo and this very distinct line. There's just no way I could have missed it before, had it been there. The curved line I mentioned in my first post is actually just visible on screen too, if the room is completely darkened.


If it's normal and supposed to be there, I will of course have to live with it. It's really just a small nuisance, but it's just that it suddenly shows up, apparantly by itself that's got me puzzled.
 

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Just thought I'd add that this is on my 1251 aswell, can be a bit annoying especially atm where im projecting directly onto a wall it's really visible. Hopefully once I get a screeen I won't notice it anymore. I was worried about the wear it mgith cause too, but by the sounds of things it'll be fine, correct?!?
 

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For these things it's a good option to have a black wall, or frame around

the screen. Sort of like overscan. Just make sure that it's very black, and

will absorb any light.


Nyder du vejret?


Nicholas
 

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If you have a non-liquid coupled pj you can tape over the line on the tube face.


No sure if it would work on a 1292.


Screen masking will help.
 

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Discussion Starter · #12 ·
Thanks Campster, Nich, Mark and Jim for your replies.


It's reassuring to hear that others have the line too, and also on 1292s.


I have been talking to a Sony tech about it, and his gut feeling was that the line shouldn't be there. He suspected ageing of components, as the pj is approaching 10 years (Perhaps also the reason the convergence takes a long time to fall completely into place). He promised to check some internal info channels to see if he could find something about it. Haven't heard anything further from him yet.


Masking the tube faces with tape is not a convenient option, as I do watch some 4:3 DVds too, and the line moves up and down with the image when I alternate between my 16:9 and 4:3 setups.


Would love to have masking around the screen, but I'm using a 4:3 dropdown screen, and as far as I know, getting such one with variable masking probably would require a bank robbery first....


Ja, jeg nyder vejret Nich :cool:
 

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Heres one for you , ive got a G70 that does it but ive just accepted it as a Sony thing as so did the 1251 i had before it . As someone said , i have a black background and it does make it less noticable but its very annoying when the sceene goes to total black .


Any ideas on how to switch it off on a G70 , i dont mind spending a few hours re-callibrating if its the case .
 
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