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Discussion Starter · #1 ·
Finally got all the HT elements together three weeks ago, LT150 92 wdhi-power and new dell 1.3gh with radeon 32ddr card. Picture is jaw dropping fantastic, even the wife was won over and has become an enthusiastic fan. Had a couple of friends over opening night, and one had to walk behind the screen (it's free standing three feet from the wall), because in his words, he had to make sure there "isnt some big ass picture tube behind there. after about 20 hrs of watching no one has yet seen rainbows or dithering, probably because every time we have about three glasses of wine or similar libations (those of you prone to rainbows, try it). Here's the problem. Ibegan to notice jerking and some tearing on slow horizontal pans. Went into radeon display menu it showed the "optimal" refresh rate being used. Went to 60hz, the picture became blurry. Walked up to the screen showing the desktop and noticed shadowing onto the pixels to the right of those being used for the wording. At 85 hz the shadowing disappeared and picture became razor sharp. But at that rate have the stuttering at times (dma is turned on). Has anyone else experienced this problem with an lt150 and htpc, and any ideas as to why the shadowy blurring at 60hz.
 

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At 60Hz, I *think* you may be seeing phase errors. Somewhere in the menus is an adjustment for this. I don't remember where.


The image I used to adjust the phase was the desktop BUT I used the "shutdown" selection on the start menu. When the screen gets dark and the dialog pops up to ask restart, shutdown, etc... The darkness is caused by a single pixel on/off black pattern superimposed over the desktop. If you see vertical stripes in this pattern, the phase is wrong.


Once you have adjusted the phase to get rid of the stripes, you can dismiss the shutdown dialog (cancel) and keep using Windows.


I hope this solves your problem.


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Huck
 

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When you change refresh rates on the fly with an HTPC (Radeon VE card) and the LT-150, you may need to 'auto adjust' the picture and fine-tune the phase. There's a button for auto adjust on the remote I think. I had the best results using 60Hz refresh, but there's the one caveat. I noticed the slight shadowing on the desktop you refer to, and I fixed that by adjusting the phase (it's buried in the advanced options somewhere).


I do know that the only refresh rates that are recommended for video/movie use are 60Hz and 72Hz as they are integer multiples of the frame rate. I have not yet tried 72Hz, but I suspect the tearing you are seeing are a result of a mismatch between vertical scan rate and frame rate. I have seen tearing when watching a DVD from a laptop (at 60Hz), but I thought that was a 'horsepower' issue. The only other thing I can think of is that somehow you may not have hardware acceleration turned on (but I think that unlikely).


Good luck.


- Dieter
 

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i agree with the above guys, LT150 OWNERS NEED TO CHECK THE SHUTDOWN SCREEN if using a HTPC.


I haven't figured out if powering up sequence makes a difference, but sometimes I have a 'phase' problem and other times do not.


Check your display with the "shutdown" screen - by far the easiest.


But if you walk up to your screen, check a windows desktop "rollover help/tool tip" thingy - thats when you mouse over an icon on the desktop and wait and then a text box appears to tell you a decsription about that file. The text in the box should be exactly 1 pixel in width - Look a a capital I or L and it should be clearly BLACK with no gray area around that vertical pixel column. If its not crisp and it looks like some gray pixels are to the left/right of the I or L, then something is wrong.


Yes, pushing the upper right button on the remote will correct this.


And out of no where I started getting the "ghosting" problem - I made my own Cat5 30 foot shielded cable (STP)according to Mr Wiggle's post - and it looked great. I go out of town a week, the wife moves stuff around, and when I come back I have a ghost on the desktop. On a std. blue desktop, when a Icon (like the while AccessDTV) is not selected, there is a minor ghost to the right.


XP800: Thx for the tip on the phase adjustment in the manual - I'll try it. I hope thats something different than the button I already push on the remote. I'll report back this weekend when I get back home.


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Jaymer...

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AccessDTV (antenna on digital input, Tivo on analog)

HTPC, P3 933 (still having DVD playing probs)

NEC LT150 (awesome)

Homemade Blackout cloth screen (from Joann's Fabrics, $6 per yard)
 

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Discussion Starter · #7 ·
Thanks to everyone for the advice. I did always auto adjust after changing refresh rate and the hardware acceleration is on full. When I have time this weekend, plan to go into the advanced menu and adjust the phase and see if that corrects the problem.
 
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