2008/04/02

MOSX: video mode wedged?

OK; this finally bit me one time too many - took me way too long to figure it out, but here it is, since I don't see it anywhere else:


For some reason, the video mode gets stuck (ex: 640 x 480 only) and you can't change it - here's how to fix it:


The info is stored in several files:

  • /Library/Preferences/.GlobalPreferences.plist
  • /Library/Preferences/com.apple.windowserver.plist
  • /Users/⟨short-name⟩/Library/Preferences/ByHost/.GlobalPreferences.⟨MAC-addr⟩.plist
  • /Users/⟨short-name⟩/Library/Preferences/ByHost/com.apple.preference.displays.⟨MAC-addr⟩.plist
  • /Users/⟨short-name⟩/Library/Preferences/ByHost/com.apple.windowserver.⟨MAC-addr⟩.plist


And there may be some in PRAM though that doesn't seem to be the case on recent systems.


To reset the video mode:

  • defaults delete /Library/Preferences/.GlobalPreferences ColorSyncDevices
  • defaults delete /Users/⟨short-name⟩/Library/Preferences/ByHost/.GlobalPreferences.⟨MAC-addr⟩ ColorSyncDevices


(Each of the above on its own line; the first requires admin.)


(Simply removing the windowserver plists has never done it for me - even from single-user mode, immediately followed by a restart and PRAM reset (multiple times). And FWIW, those files have still not reappeared on my system; perhaps they're no longer used.)


Why might this happen? It's probably related (at least in my case) to moving a boot volume from one system to another - that has a different video card. Which means this might be of some help for moving from one machine to another (ex: upgrade) or deploying an image to multiple machines.


NB: The above info is from a Mac OS X Server 10.4.11 system, though at least most of this should apply to Mac OS X (Client) as well, and other releases.

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