External monitor shows black screen

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External monitor shows black screen

Hey fella's,

I have an early 2011, 11'' Macbook Pro running Yosemite 10.10.1, which I've been hooking up to an IPS226 LG Flatron external monitor.

It did a number on me last week: the external monitor decided to show only a completely black screen. Like it's in power saving mode, except it isn't: the Mac recognises its existence, the laptop's monitor becomes a secondary screen. When I unplug the external monitor, it says "switching to power saving mode" and then goes black again...

Here's the kicker: I tried hooking it up to other laptops using different cables (mine is HDMI, so I tried VGA to another laptop) - worked like a charm. Then, when I plugged mine back in, also worked! Until today. Now it's happened again. What sorcery is this?

Thanks!

MacBook Pro (13-inch Early 2011), OS X Yosemite (10.10.1)

Posted on Jan 11, 2015 11:20 PM

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Answer 1

Best reply

chuck_3rd

Community Specialist

Jan 13, 2015 8:52 AM in response to Polindrom

Hi Polindrom,

To troubleshoot this issue where the external display you're using with your Mac appears blank, please follow the directions outlined below.

No video or no signal, image distortion, "snow," or flickering

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 resolution

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.

Apple computers: Troubleshooting issues with video on internal or external displays - Apple Support

Thanks for using the Apple Support Communities!

Cheers,

Alex H.

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Answer 2

Polindrom Author

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Jan 14, 2015 3:42 AM in response to chuck_3rd

Alrighty, so, great answer - thanks. Followed the instructions, nothing worked until I retried playing with the resolution. Then it agreed to display my screen again, under 720p. Kind of weird, and when I use the built-in display side by side with the external monitor, the resolution seems different on the external monitor (everything is much bigger). But I'll take it.

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