Hey newbieappleuser13,
Thanks for the question. After reviewing your post, it sounds like you are having trouble with an external display. I would recommend that you read this article, it may be able to help you resolve or isolate the issue.
Apple computers: Troubleshooting issues with video on internal or external displays
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:
- 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).
You can reset the Mac's parameter RAM and SMC.
Start 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.
Thanks for using Apple Support Communities.
Have a nice day,
Mario
