I have a macbook pro 13-inch, Aluminum, Late 2008, and ever since I have updated to OS X I cannot connect my dual monitor...nothing has changed in my set up and it worked great until the update completed. Am I missing something?
Hello there, ballenbd.
The following Knowledge Base article offers up some great information for troubleshooting issues with an external display:
Apple computers: Troubleshooting issues with video on internal or external displays
http://support.apple.com/kb/ht1573
Check connections
When using an external display be sure to check the following:
- If you're using an Apple notebook, confirm the AC power cable or adapter is securely connected to the computer and the cable providing power to the display is also secure. It is always good to have your notebook connected to AC power when an external display is in use.
- Confirm display adapters are fully seated in their respective connections and that they are supported models and for the computer and display. Refer to these articles to assist you with adapter compatibility and further configuration information:
- Monitor and Display Adapter Table
- About Mini DisplayPort to HDMI adapters
- Apple Mini DisplayPort adapters: Frequently asked questions (FAQ)
- Thunderbolt ports and displays: Frequently asked questions (FAQ)
- Remove all display cable extenders, KVM switches, or other like devices and retest to determine if the issue is resolved.
- Try unplugging the video adapter or cable and then plug it back in.
- If more than one video adapter is in use (or "daisy-chained"), troubleshoot by using only one adapter.
Example: A mini DisplayPort to DVI adapter connected to a DVI to HDMI adapter is an unsupported configuration because there is a series of adapters in use.
- If available, try using a different display and or adapter (or use a different connector by using DVI instead of VGA, for instance).
Reset the system
You can reset the Mac's parameter RAM and SMC.Reset the resolutionStart by resetting the Mac's parameter RAM. If the display does not come up, was previously set to an unsupported resolution, and still results in no video:
- Start up in Safe Mode.
- From the Apple () menu, choose System Preferences.
- Choose Displays from the View menu to open the preferences pane.
- Select any resolution and refresh rate that your display supports.
- Restart your computer.
Helpful related articles
These articles may offer additional assistance and information about displays and video adapters:
- Apple Portables: How to use your computer in closed lid mode with an external display
- Apple Cinema Display (30-inch DVI) has 1280 x 800 as the maximum available resolution
- Mac Pro (Early 2009), Mac Pro (Mid 2010): Supported display configurations
- For assistance with Retina displays, please see Frequently asked questions about using a Retina display.
If you tried all of these steps for your display and the video issues persist, contact Apple technical support or take your Apple computer to the nearest Apple Store or Apple Authorized Service Provider (AASP) for diagnosis. If you plan to visit an Apple Retail Store, make a reservation at the Genius Bar using http://www.apple.com/retail/geniusbar/ (available in some countries only).
Note: Diagnostic fees may apply for issues not covered under warranty or the AppleCare Protection Plan (APP).
Thanks for reaching out to Apple Support Communities.
Cheers,
Pedro.
Macbook pro 13-inch, Aluminum, Late 2008 Dual Monitors
