Can't set monitor resolution to 1900x1200

I've tried turning off colour management on the Gefen Scaler, but no luck.

Looks like I'll have to go back to the days of unplugging cables constantly than using a £200 scaler and switcher all thanks to a shoddy update of Mac OS X.

I am having this exact same problem

After the update, only TV resolutions are available for output to my Gefen HD Mate scaler

I managed to get it working through a 3rd-party 'hack'

Original thread: http://discussions.apple.com/thread.jspa?threadID=1943728&start=0&tstart=0

SwitchResX: http://www.madrau.com/html/SRX/About.html

You have to create a custom group of settings.

What I did was:

• Make sure correct monitor is selected
• Click Export EDID and open in TextEdit
• I wanted the resolution 1920 x 1200, so search for that in the file. I found a line that read:
Descriptor #3 is Timing definition:
Mode = 1920 x 1200 @ 59.950Hz
• Below that it should mention things like Active, Front Porch etc
• Copy all of those settings into a new Custom profile (Custom tab in ResX)
• Apply that, restart.
• Go back to ResX and make your profile (mine was at the bottom of the list) and click the left most area to mark it with a black dot and make it active.


Hope that helps.

Yep - as the originator of that thread - There appear to be two ways around - Use Analog (VGA) or hack - I personally haven't succeeded with the hack, but I'm also not that inclined to do it.

The driver needs fixing.

Yes I tried using VGA as well and it was unusable. Unfortunately you might have to follow the advice (great writeup by the way) on how to use switchresx to force it into seeing the correct resolutions.