DVI/HDMI on SAMSUNG A650

It's unlikely the cable. Check the picture setting in your menu, I use what Samsung lables as "Just Scan" which is 1:1 pixel setting and it works perfectly fine with 1920x1080p.

I wanted to add to this old thread. I use my Samsung 630 for HTPC applications, and had been using a standard DVI --> PC cable for a while. It worked flawlessly and the image made full use of the entire screen.

I hooked up a DVI --> HDMI cable today, and I experienced underscan issues. I tried different display methods, including 16:9 and Just Scan. None fixed the issue.

I have no resolved the problem, and I wanted to leave this post in case others run into this issue.

1) I had to load the ATI Catalyst Control Center in advanced mode
2) I expanded the "DTV (DVI)" Option on the tree at the left of the window
3) I chose the "scaling" option from the "DTV (DVI)" tree
4) There is a slider in this window, with the default being 7% Underscan...I slid it to the right as far as it would go (0% Underscan, 0% Overscan)
5) I didn't check the box at the bottom, but it wouldn't hurt to do so.

Hit "Apply" and then hit "OK." You should be good to go.

I had the same issue with my A630. I tried both 16:9 and just scan but my screen would not fill. In the end I had to slide the scaling slider all the way to the right and it fit perfectly. Is there any down side to doing this? I am just worried its stretching the pixels and not providing a correct 1:1 mapping.

To check your 1080p display for 1:1 pixel mapping and scaling issues...try this:

1080p Test Image #1

Set the image as your background (if you do this, it's important to put the background mode to "Center" or it will stretch it out even on your TV regardless to match your PC display, which is 16:10) or open it in regular old Windows Picture and Fax viewer (the default image viewer in windows) and F11 it for fullscreen.

The picture contains thousands of individual horizontal lines that should show equal spacing between them, as in all lines and spacing should be equidistant. Lines should all appear the same thickness as well as the spacing between them.

An easier test for overscan is to just move the mouse to the far edges of the screen. The mouse cursor should just stop at the edge of the screen, without so much as 1 pixel leaving the border. Also, drag a selection box on the background...each "dot" should show up as an individual pixel, they should all be spaced the same, the same size, without any funkiness.

Another test for overscan and 1:1 pixel mapping:

1080p Test Image #2

In this test, do the same as you did for the first by setting it as your background with "center" mode, since it's a 1920x1080 image. Look at your TV. You should be able to see the entire circle, and out to where it says 1920x1080 on the top left. The text should appear very crisp, the boxes should all be equal, and everything in general should look correct with no funkiness. Namely the individual lines above and below the color gradient in the middle should still appear individually, with the same amount of space between them. They should not merge/disappear/look funky in the least.

BTW, I did get your PM about the a630 AMP stuck on bug. I have errands to run right now but I'll post on my original thread about it later.

Hope this helps.

PS - Setting the ATI CCC to 0% scaling (slider all the way to the right) IS the correct option. Everything should look just how it does compared to your PC monitor. This is how I run my HTPC. Believe me I am a hater of any incorrect scaling, as nothing but 0% scaling will acheive 1:1 pixel mapping. I've returned a TV because it could not display 1080p without overscan...which isn't what I consider Full-HD. Because...it was effectively still scaling (stretching!) the source whether it's from the PC, Blu-Ray, etc. Unacceptable.

I am having this issue too with my samsung, when I connect the PC to my TV via a DVI to HDMI cable I do not get a full screen at 1920x1080. I get the black border around the edges. Weird thing is when I go into my CCC manager I do not see a scaling bar under the DTV option.

Also if I switch cable and use VGA on my video adapter ill get a fullscreen at 1920x1080. I just cant get it with the DVI/HDMI cable.

Any ideas? A

Does the HDMI 1.2 vs. 1.3 make the difference? I have an Ln52a630, and the manual says that a cable which is not 1.3 may cause flicker or no image for DVD player connection. But the manual does not say anything about the PC connection. Monoprice.com has a nice selection of DVI-HDMI cables, but they are all rated 1.2. Any issues with those? Does DVI-to-HDMI-1.3 even exist?
Update: spoke to a tech rep on Monoprice web site, and he confirmed there is no such thing as DVI-to-HDMI-1.3. It's going to be HDMI 1.2 and it should work fine.