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Discussion Starter · #1 ·
Overall I have been very pleased with the PQ I have achieved with my HTPC setup. However, I have been mildly dissappointed by bends in vertical lines, especially those along the left and right edges in the screen. At first I thought this had to do with either a poor transcoder (I have the lowly RCA VHD300) or a need to further tweak Powerstrip. But the image generated by MyHD exhibits the same characteristics (maybe not quite as pronounced), and MyHD's output does not go through the transcoder, but instead feeds the 2nd component input of my HDTV set through a VGA breakout cable.


So... what's up with this? My HDTV set didn't exhiit this vertical line distortion in the past, when I fed it component from my old DVD player or when I watched regular NTSC TV. What usually causes bends in vertical lines, and how can it be corrected?
 

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What TV do you have?


Some HDTVs, most notably some of the older Toshiba models like mine, have different convergence memories for 480P input than for "true HD" input.


"True HD" is either a 1080i or 540P signal. I had to fix the geometry and convergence on mine after I hooked up the HTPC.
 

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Discussion Starter · #4 ·
Thanks jvincent. I may have to see what I can dig up about my Samsung TXM3281HF's service menu. From what I recall while researching this set, it doesn't expose the service menu to mere humans, and might have some convergence issues, as this Google thread reports. I guess I didn't have this problem before because I wasn't pumping anything higher than 480i (my DVD player was non-progressive scan).
 

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Discussion Starter · #5 ·
I did some further investigation and have found the following:

1) The service menu is accessed, with power OFF, Mute-1-8-2-Power.

2) My problem doesn't seem to be a convergence issue, but a geometrical one: the lines are wavy in sections without discoloration or color-shifting.

3) None of the service menu options had any positive effect on the wavy lines.


So... I'm beginning to wonder what else could be causing this issue. Could a bad/poor transcoder cause this? Until I can upgrade, I am using the lowly RCA transcoder.
 

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Have you tried playing the test patterns off the AVIA DVD (or similar) in both 480P and 540P modes to see if they are different? If they aren't then it may be something is just set incorrectly. Most TVs have several levels of geometry control.


Again, I'm not familiar with the Samsung, but somewhere in the service menu you may also be able to adjust the geometry/convergence via a grid.


For most TVs there are 3 grids (R,G, B) that can be called up adjusted independantly.


Do one colour (R or G) then match R to G (assuming you did G first) then match B to R and you should be done.


Assuming your first grid is "square" then once you're done this procedure you are not only converged but you also have proper geometry.
 
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