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sj64
Joined: 02 Jan 2008
Posts: 34
Location: Sydney, Australia
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| Posted: Fri Apr 11, 2008 12:51 am Post subject: Getting the green to focus? - NEC XG1100 |
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Hi guys,
I just recently bought a NEC XG1100. This last week I've been setting it up, and the last thing I want to sort out is the side focus on the green crt?
I can get the center (middle, top, bottom) all in great focus, at about +10. And the red/blue crt's are good all over. But the green sides are not so good. The right side is worse than the left. Starting from the middle of the screen, the image progressively loses focus until geometry lines on the edge are about 3-4 times wider than the red or blue lines they sit over. This is with side focus maxed at +100.
I'm sure it's an electronic issue rather than physical setup, I can see the defocus when I look down the lens onto the tube face.
Does anyone have any ideas? Could there be an adjustment for this in the menu, or possibly via a trim pot on one of the boards?
Also I'm wondering if maybe I should try shifting the image to use a different portion of the tube face. That's a last resort though, because I've fairly maxed the r/g/b rasters. To shift the image a reasonable amount I'll have to shrink the raster (or increase my porches) and move the whole pj back.
'cheers
Sim.
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MikeEby
Joined: 24 Jun 2007
Posts: 5237
Location: Osceola, Indiana
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kschmit2
Joined: 09 Mar 2006
Posts: 1141
Location: Heidelberg, Germany
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| Posted: Fri Apr 11, 2008 6:59 am Post subject: |
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Mike, that reminds me that I have to update the XG section of that guide 
Kai
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dropzone7
Joined: 12 Jun 2007
Posts: 1069
Location: Charlotte, NC
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| Posted: Fri Apr 11, 2008 12:04 pm Post subject: |
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| kschmit2 wrote: | Mike, that reminds me that I have to update the XG section of that guide
Kai |
Yes and I HOPE to be needing it soon!
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dropzone7
Joined: 12 Jun 2007
Posts: 1069
Location: Charlotte, NC
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| Posted: Fri Apr 11, 2008 12:09 pm Post subject: Re: Getting the green to focus? - NEC XG1100 |
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| sj64 wrote: | Hi guys,
I just recently bought a NEC XG1100. This last week I've been setting it up, and the last thing I want to sort out is the side focus on the green crt?
I can get the center (middle, top, bottom) all in great focus, at about +10. And the red/blue crt's are good all over. But the green sides are not so good. The right side is worse than the left. Starting from the middle of the screen, the image progressively loses focus until geometry lines on the edge are about 3-4 times wider than the red or blue lines they sit over. This is with side focus maxed at +100.
I'm sure it's an electronic issue rather than physical setup, I can see the defocus when I look down the lens onto the tube face.
Does anyone have any ideas? Could there be an adjustment for this in the menu, or possibly via a trim pot on one of the boards?
Also I'm wondering if maybe I should try shifting the image to use a different portion of the tube face. That's a last resort though, because I've fairly maxed the r/g/b rasters. To shift the image a reasonable amount I'll have to shrink the raster (or increase my porches) and move the whole pj back.
'cheers
Sim. |
I could be wrong here but I believe that good center focus should be achieved somewhere around 0 to -10. I would zero out all of your electronic focus adjustments and then adjust the focus pots so that good focus is within these parameters. Then you can use the electronic focus controls to fine tune within that range. Now for edge and corner focus I would refer to the document Mike mentioned as that sounds like astig and or flapping. Not that the XG really has flapping but you might double check that your lens spacers are in the correct position for your throw distance and screen size.
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Curt Palme
CRT Tech
Joined: 08 Mar 2006
Posts: 24396
Location: Langley, BC
TV/Projector: All of them!
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| Posted: Fri Apr 11, 2008 4:00 pm Post subject: |
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Your focus board is bad. Very common on these units. I wouldn't touch the astig, it's the focus board. I can repair it if you want..
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kschmit2
Joined: 09 Mar 2006
Posts: 1141
Location: Heidelberg, Germany
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| Posted: Fri Apr 11, 2008 5:18 pm Post subject: |
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yeah, I shall add some BIG caveats to my Astig guide as well
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sj64
Joined: 02 Jan 2008
Posts: 34
Location: Sydney, Australia
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| Posted: Sun Apr 13, 2008 4:27 am Post subject: |
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Hi guys,
thanks for the responses.
A few days ago I found this topic from Curt, 'Mo Better Focus':
https://www.curtpalme.com/forum_archived/viewtopic.php@t=923.html
Thanks for that posting Curt.
The gists of it seemed to be the idea of adjusting the astig for focus rather than getting those perfect round dots. I.e. when adjusting the astig, particularly on the edges, bring up instead a focused test pattern like the 'H' pattern and adjust the astig to improve the focus.
This makes sense to me, seeing as astig adjustments are simply a means to better focus anyway.
So I tried this on my XG, getting a focused external test pattern on screen worked just as Mark_A_W suggested. And it did help somewhat. Still not ideal, but noticeably better than what focus was before. I 'spose it doesn't really matter that the little round defocused dots for astig on that right edge have now become horizontal streaks, if the focus improves.
I'm about to go overseas on holidays for a month. When I get back, depending on my level of debt  - I wouldn't mind getting the focus board fixed.
And two quick questions:
-As I am going away for about 5 weeks, what's the general consensus - Leave the pj plugged or unplugged?
-Also the pj makes this really soft 'ticking' noise about every 8-15 sec. I only hear it when the room's silent. Not certain, but I think if I mute the picture, the clicking slows down. I've opened the pj and in a dark room I can't see any arcing or such. And I've yet to swing the top boards up for a closer inspection, but listening from above the noise appears to be coming from in or around the bell part of the green crt.
Any ideas what it might be, and should I worry about it?
'cheers
S.
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Mark_A_W
Joined: 15 Mar 2006
Posts: 3068
Location: Sunny Melbourne Australia
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| Posted: Mon Apr 14, 2008 3:26 am Post subject: |
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Sounds like a fan.
Unplug it.
Umm...remind me, what did I suggest?
I'd loan you an F-drive to test, but my spare F-drive is not compatible. Sorry 
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MikeEby
Joined: 24 Jun 2007
Posts: 5237
Location: Osceola, Indiana
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| Posted: Mon Apr 14, 2008 3:34 am Post subject: |
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| Mark_A_W wrote: | Sounds like a fan.
Unplug it.
Umm...remind me, what did I suggest?
I'd loan you an F-drive to test, but my spare F-drive is not compatible. Sorry |
By reading your post it sounds like you said to unplug the fan. I had a terribly noisy fan on the green neck board that I had to replace.
Mike
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Doing HD since the last century!
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Mark_A_W
Joined: 15 Mar 2006
Posts: 3068
Location: Sunny Melbourne Australia
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| Posted: Mon Apr 14, 2008 3:41 am Post subject: |
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Sorry I meant unplug it when leaving it for 5 weeks.
I unplug mine whenever I'm not using it. It can be weeks between films for me...
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sj64
Joined: 02 Jan 2008
Posts: 34
Location: Sydney, Australia
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| Posted: Tue Apr 15, 2008 3:41 am Post subject: |
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Thanks for the repsonses,
I will unplug it then, tonight in fact, right after one last movie before going away tomorrow.
Mark I think you did suggest the possibility of the 'ticking' being a fan noise. I'd love to make a recording so you guys can hear it, but I tried with my camera and ambient fan noise drowns everything out.
I'll just have to find it. -Wonder if those toy stethoscopes are any good...
'cheers
Sim.
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AnalogRocks
Forum Moderator
Joined: 08 Mar 2006
Posts: 26706
Location: Toronto, Ontario, Canada
TV/Projector: Sony 1252Q, AMPRO 4000G
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| Posted: Tue Apr 15, 2008 3:44 am Post subject: |
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| sj64 wrote: | Thanks for the repsonses,
I will unplug it then, tonight in fact, right after one last movie before going away tomorrow.
Mark I think you did suggest the possibility of the 'ticking' being a fan noise. I'd love to make a recording so you guys can hear it, but I tried with my camera and ambient fan noise drowns everything out.
I'll just have to find it. -Wonder if those toy stethoscopes are any good...
'cheers
Sim. |
You can do it with a screwdriver. Place it against the fan and against your microphone it may record the noise for you.
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HD done right!
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Mark_A_W
Joined: 15 Mar 2006
Posts: 3068
Location: Sunny Melbourne Australia
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| Posted: Tue Apr 15, 2008 8:32 am Post subject: |
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There is a fan below the green tube (all tubes have a fan) Sim.
I would pull out the powersupply and check the fans first.
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