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Discussion Starter · #1 ·
I have this monitor and it has about 5mm of vertical bow at the center of the bottom of the screen. Is there any way to rectify this?


I bought the service guide and couldn't find any mention of what can be done to fix this problem.


What is the Princeton spec for this error?


akula
 

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Are you talking about the little "point" in the middle of the bottom of the screen (it's part of the tube/mask)? For all inputs??

There isn't any geometry you *can't* adjust (or mask) on this set; is it really that bad?
 

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Discussion Starter · #3 ·
Stanton,


No, I'm not concerned with the small notch in the mask.


The upwardly bowed scan lines at the bottom are very annoying, however. The monitor is adjusted so that the lower edge of the image goes though the lower right and left hand corners of the viewable area, but it is more than 5mm above the bottom (of the viewable area), mid way between left and right. It is not a small effect. And yes, it is really bad. I've tried to ignore it, but without success.


You are right, there are lots of controls to rotate the image and to make sure the right and left edges of the image are vertical. Most are available with the second remote, some are internal adjustments only.


After having studied the circuit diagrams, I'm pretty sure there are no electronic adjustments to correct for vertical bow of horizontal lines.


I use the monitor mainly to view HDTV and (anamorphic) DVDs (RGB and YPbPr2 inputs respectively). The problem occurs for both inputs. Even though the bottom of the DVD images is some distance away from the bottom of the viewable area, the curvature is readily apparent.


Using overscan to hide the problem for HDTV works, but if I were to depend on mask positioning to deal with the problem with DVDs, I would have to make the adjustments for just about every different one, which makes this approach inconvenient to say the least.


I should mention that the scan lines at the top are also bowed up in the middle, but it is much less severe.


akula

Quote:
Originally posted by Stanton
Are you talking about the little "point" in the middle of the bottom of the screen (it's part of the tube/mask)? For all inputs??

There isn't any geometry you *can't* adjust (or mask) on this set; is it really that bad?
 

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Akula,


I own the Sampo 34" widescreen, and I have a similar problem, but my scanlines bow DOWN, not up. I, too, have the service remote, and I've tried everything, but I can't get rid of the bow, either.


Any other Sampo or Panasonic owners have these conditions, and if so, does anybody have a hint on how to get rid of it?


Thanks in advance,


Ron
 

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I too have the Sampo 34" and my bow lines are horrible, not only that the geometry is whacked out even worse recently when the resolution changes from 720 to 1080, in fact even today I had to shut everything down to get the TV to kick back into 1080. I use a Samsung SIR-T150 and a Explorer 3100HD cablebox, also a RP91 dvd player and my kids play xbox all on this tv. It got so bad today and after seeing a continual degradation of the geometry completely I called Sampo for service. I think the TV is dying slowly. It is about 2 months old now. I am now getting bright vertical lines near the edge of the screen that will not go away unless I overscan during full16x9 viewing. Watching 2.35:1 movies on HBOHD is impossible, the bow is almost 3/4" in the top of the picture bowing down. Horrible pq.



Mr. Crowley
 

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Mr Crowley,


Do you have the updated chassis on your Sampo? I had really bad distortion on both vertical edges. I called Sampo service and described the problem, and they immediately said that they'd replace the chassis with a newer one. The new one has an S-video input on the back (old one did not). Anyway, they didn't totally eliminate the problem, but it is significantly improved...


I haven't noticed a gradual degradation, as you suggest yours is doing.


Is there anyone from Sampo out there that can please shed some light on what we can do about the bowing scan lines?


Thanks in advance,


Ron
 

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Yes Ron, it does have the svideo on back. Sure hope they send a sharpeyed tech. The service remote you have, what did they charge to send you that?



Mr. Crowley
 

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Mr Crowley,


I bought the set used (demo), and they threw it in with the sale...


However, I did buy another remote from Sampo, so perhaps that will help gauge how much a service remote could set you back. The remote that came with my set only had a single 'input select' button, and all it did was 'go to the next input', which was tortuous because it was so slow. I had seen a posting on this forum that some of the newer sets had a remote with individual buttons. I contacted Sampo, and they told me that it would work with my set, also. They charged me $20 plus $10 shipping and handling, so for $30 it was a great upgrade.


The service remote only has one button on it that the normal remote doesn't, and all it does is get you into and out of service mode. Others have posted how you get into service mode without this remote, so you really don't need it.


Ron
 

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Yes, quite a huge amount of answers about the sampo 34 and the service menu were in this thread, what a find! I Saved the whole thread for reference in mhtml. Phew thanks to everyone who contributed to this subject and all the other great posts of enormous info located here at avs.



Mr. Crowley
 

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Hi,

I 'm one of those who posted on this subject. Although ZenJen and others have alluded to volumes of info on using the Sampo service menu, I have yet to see anything comprehensive posted. I'm a new Sampo owner and like you would really like to know how to get rid of that annoying bowing problem...Anyone know?


Mark H
 

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I will update you when it is serviced, But from what I have gathered there hasnt been a way to get it fixed through the service menu. Lets just hope there is a internal pot adjustment to correct it, I certainly will have a clear description of what the service person does if it is corrected, if not though I will be getting this unit replaced with a display that does not have this flaw.



Mr. Crowley
 

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Akula,


Back to your problem.


The new Princeton Graphic's monitors have a 'BOW' adjustment.


You are probably describing horizontal lines that are not straight but curve upward in the center.


I am not an expert but it is my understanding that adjustments for this condition are made by adjusting the magnetic rings (7?) on the neck of the picture tube (not for amateurs). These rings also control convergence so the combined adjustments are critical. I have seen this done but there are limits as to what can be done, particularly on flat screens. Magnets can also be placed on the back of the picture near the neck.


A good tech that understands what you want and is willing to spend time can probably correct the problem.


There is a thread on the forum that points to TV adjustments and it covers the above issue. I don't remember where it is but I'll try to find it.


Good luck,
 

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A repair tech came to look at the Sampo 34" and could'nt fix it. He said Sampo was sending him a service manual and would get back to me, however I havent heard from him in over a week, looks like it is a flaw in the set?



Mr. Crowley
 

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"I have had my 34" Sampo for over a year and have yet to see anything less than amazing picture quality.


YMMV,

Paul"



Sampo just returned my phone call and are going to replace the set, apparently it is not something a field tech can repair, so looks like Sampo has some very very good customer service as well as an excellent product.


I bought this TV based on the postings here and what the specs were, and I know Sampo will certainly pull through and we will be as pleased as you have been Paul.



Mr. Crowley
 
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