Trouble connecting MacBook to a Samsung 27'' TFT

Question

Hi people.
I often connect my 1,83 Core Duo MacBook to a Samsung TFT display using the Mini DVI to VGA adapter and an VGA cable, in order to watch DVDs, AVIs, high definition podcasts and that kind of stuff on a bigger screen.
The MacBook and the Samsung seem to like each other, as they instantly start to work together. But there's a little issue I just can't imagine how to work out.
The resolution of the external TFT display is 1280 x 768 and the Mac gives me the option to select it at different refresh rates. And here comes the problem:
When I select 1280 x 768 at 60 Hz, the image looks clean and crisp, but it appears displaced to the left. I mean, I loose part of the desktop on the left, and I see a narrow black column at the right of the external screen.
At 85 Hz the desktop fits the screen perfectly, but the image is a little blurry. I can work that way, but I don't like losing the crispness, and when I watch video I can actually see the frames refreshing.
At 75 Hz I have both problems, and higher refresh rates are not supported by the Samsung TFT.
Any clue about how can I work it out?
Thanks!

Answer 1

Here are some details of an exact timing to try that I have used successfully on a 1280 x 768 Samsung TV. Maybe they will work for your TV.
Pixel clock: 80.13 MHz
H Active: 1280 pixels
H Front porch: 64 pixels
H Sync width: 136 pixels
H Back porch: 200 pixels
V Active: 768 lines
V Front porch: 1 line
V Sync width: 3 lines
V Back porch: 23 lines
H Sync is positive
V Sync is negative (no check mark in box)
Interlace is off (no check mark in box)