DVI Extender, no image

I want to use the DVI extender to output the screen of my 2009 iMac via the Displayport to DVI adapter. The resolution i'm using is 720X576(PAL) with a field rate of 50Hz. But nothing shows up on the SDI output.

Does anyone know what the problem could be? The iMac is able to find the DVI Extender as a second screen and it gives me the options of selecting different kind of resolutions. The DVI Extender itself is also set to output video.

This might be an incompatibility issue. I have used DVI Extender solutions from KVMSwitchTech in the past with great success. However in my case I had DVI in and DVI out( no adapters or converters).

You will have to set your video card refresh rate to 25hz and Interlaced if you want to use this resolution. To test set the output to something you can be sure is smpte standard ish- like HDTV resolutions that show up as such on your computer (ie they say 1080i50) and test the unit from there. Getting reliable SD signals from earlier macs, especially those without dedicated video cards is quite difficult. The display mode you need is not really supported with many of the video cards. You can try something like swtichresx to get more control over it. Oh and just in case make sure you have the USB plugged in to the DVI extender, that is how it gets its power.

Fred

What are you trying to output to?

I'm trying to output to an SD videoswitcher.

Sounds like it could be an EDID issue. Try this http://www.dviparrot.com/ I don't know why these things are not mentioned here more as I'm sure most converter issues are because of EDID. Here is the thing the SDI is unidirectional so the Switcher can't tell the converter what resolution it needs so the converter can't tell the computer what to send when it asks. So it will just convert whatever the computer sends even if that is unusable by the switcher. This is where the DVI parrot comes in it will tell the computer I want x resolution send me nothing but that.

If you look at what your computer sees as the resolution of the attached device or check to see if it even sees the dvi extender that might give you an idea of the problem
Sharyn