February 27, 2008 12:38 PM PST

Mac OS X 10.5.2 Special Report: Missing display resolutions

by CNET staff

Some users have reported disappearance of previously available screen resolutions. One reader writes:

"I'm using a MBP (latest) with a NEC Spectraview 2690. Plugged in using 10.5.1 - running 1920 x 1200 / 60 Hz via DVI. Fine. After update to 10.5.2 the highest resolution 1440 x 900 and 'Standard LCD'."

It is difficult to determine whether this issue is caused by Mac OS X 10.5.2 or the Leopard Graphics Update that accompanied it. A thread on the MacFixIt forums is now tracking the problem, with reader Philip Chadwick writing:

"Using an external via DVI that supports 1680 x 1050?it actually worked fine after the 10.5.2/video updates, but today, after a hard crash/reboot the resolutions above 1400 x 900 were missing. Re- detected displays, reset PRAM, rebooted and cleared caches...nothin'."

We've notes from dozens of other readers who report the issue.

Fixes

Shut lid immediately Since this problem generally occurs on notebooks with external displays, one workaround involves the following: Press the power button on your Mac (with external display connected) then immediately shut the lid. Your Mac will continue booting and the external display should show the proper resolutions.

Now, open your Mac's lid and go to System Preferences, then select "Displays" and press the "Detect Displays" button. You may now be able to boot normally with all previously available resolutions.

Reset SMC Instructions for:
MacBook and MacBook Pro

MacFixIt reader Philip Chadwick writes:

"An SMC reset solved the problem on my MBP 2.4GHz."

"I use a Samsung Syncmaster 191t as a desktop expander to my MacBook Pro. Two days ago, I used my MacBook Pro to drive a projector, and when I reconnected the Samsung, the screen resolution for the Samsung, 1280x1024, was missing from the list. Spent an hour and $50 with Apple support. After a PRAM reboot (?) and lots of time with disk utility, it is finally working again..."

To reset PRAM/NVRAM, shut down your Mac, then start it back up while immediately holding the following keys: Command, Option, P and R. Hold the keys down until the computer restarts and you hear the startup sound for the third time.

Delete a specific cache We've also received word that deleting the following, specific cache file:

/System/Library/Extensions/Caches/com.apple.kext.info

can resolve this issue. [Thanks Fredrik]

Downgrading to Mac OS X 10.5.1 or removing the Graphics update If this issue proves too disruptive to your workflow, follow our tutorial on reinstalling the system then update to Mac OS X 10.5.1. We've received some reports that upgrading to 10.5.2 but refraining from installing the Leopard Graphics Update alleviates this issue, indicating that the graphics update is to blame.