When Mac users plug the monitor cable, MacBook screen flash and not detecting any external monitor. External monitor display goes black.
Devices: MacBook Pro 15″ Mid-2010, iMac, Cinema HD Display, dell monitor, LG monitor, ViewSonic HDMI monitor, OSX Mavericks, OSX Yosemite
Use Detect Display option (hidden in Display preference panel).
Go to System Preferences -> Displays. Hold down “option” key. ‘Detect Displays’ button should appears in the bottom right.Click it.
- Unplug all devices from laptop include power adapter.
- Turn off Bluetooth.
- Do PRAM/NVRAM resets and then SMC resets.
- Then plug in all devices back in one at time.
- Now enable Bluetooth.
Run your external monitor at its native resolution when the internal display is off.
Solution 4:- (For Samsung SyncMaster)
Unplug the power cable from Samsung syncmaster. Then plug in the mini display adapter.
No do a “Detect display” in system preferences to check if it detecting it. Then close the lid in the laptop and plug in the power to the syncmaster. It will “detect” the monitor.
1. Unplug the monitor power and disconnect mini-display port from your computer.
2. Wait until power distinguishes on the external monitor (even the standby light)
3. First plug in mini-display port. The external monitor should always work now even though sleep and shutdown.
- Install and use gfxCardStatus to ensure “discrete only” mode to detect the external HDMI monitor.
- Clear the System preferences (Restart and press Option + Command + P + R)
- Shut down all devices and unplug from MacBook Pro. Wait 3 minutes. Now plugin. Power on you computer while holding Shift key to start in safe mode. Then restart computer in regular mode.
- Change new DVI cable.
- If you are connected 2 desktop with MacBook and your MacBook Pro doesn’t detect TV, turn off on display.
- Remove Diablo 3 (game) and turn off “Anti Aliasing”.
- Reboot MacBook and change the screen resolution.
- Launch monitor detection with Cmd+Shift+E keys, wait few seconds. Unplug and re-plug the external monitor.
If you have any other problems or solutions about external monitor detection issue, do let us via comment.