How do I get my Mac to auto-detect my monitor again?

March 30, 2008 8:36 AM

My Mac no longer auto-detects monitor and resolution after trying out SwitchResX. How can I get this working again without reinstalling OSX?

I have a Mac Mini with 10.4.11 hooked to an HTDV (resolution 1366x768) with a VGA cable.

The first time I hooked it up the Mac automatically detected the correct monitor (the model name and number showed up in the Display preference pane) and it set the resolution correctly to the native.

I wanted to try and get it working on one of the HDMI ports, and part of that process led me to install SwitchResX. I gave up on this and went back to the VGA port and uninstalled SwitchResX, then restarted the computer.

Now the Mac no longer detects the display correctly. Instead it's shown as a "VGA Display" and the native resolution is not one of the options any more.

I tried reinstalling SwitchResX since it shows product and vendor information too. However, this now shows up as "unknown" as well.

I've tried to repair disk permissions without any luck.

Can I reinstall something from the OSX disc, perhaps with Pacifist, to get this working again? Are there preference files I can delete so they will be recreated?

Thanks very much!

posted by odinsdream to computers & internet (5 comments total)

Thats, um, an HDTV, not an HTDV.
posted by odinsdream at 8:37 AM on March 30, 2008

Have you clicked the "Detect Displays" button in the Displays control panel? I ask because you didn't specifically say you've done that.
posted by infinitewindow at 8:54 AM on March 30, 2008

Yes, I have done that.
posted by odinsdream at 10:14 AM on March 30, 2008

Step Zero: in switchrezx, hit "reset to factory defaults"

Step One: Remove Application Enhancer (sorry, it breaks tons of things, and will continue to do so, especially if you plan on upgrading to 10.5 in the future):

Step Two: make sure you've deleted the prefpanes from both ~/Library/PreferencePanes and /Library/PreferencePanes

Or if you haven't tried it, run its own uninstaller, as it will cleanup after itself. (hopefully)

The preference plists to delete are: fr.madrau.switchres.dameon.plist and fr.madrau.switchres.app.plist
posted by mrzarquon at 11:29 AM on March 30, 2008

mrzarquon:

Well, the order might be a bit different, but I've removed SwitchResX and I've also hit Factory Reset inside it (after re-installing it). I've also removed and re-installed Application Enhancer, with reboots in between all of these steps to make sure things weren't fixed.

The thing that might not be clear: I don't need or want SwitchResX, I was just trying it out to see if it would solve some of the HDMI problems I was having. It seems like SwitchResX is what initially messed up the built-in detection (or the definitions that the detection uses), and uninstalling it (using the uninstaller it provides) didn't fix the issue.
posted by odinsdream at 1:23 PM on March 30, 2008