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Monitor - Connecting to a Mac

Operation
Monitor - Connecting to a Mac

This article covers how to connect your LG monitor to a Mac.


Identify which Apple adapter and cable you need to connect the Mac and the monitor by following the guidance below.

  1. Plug the monitor in.

  2. Open System Preferences > Displays.

  3. Click the Arrangement tab.

  4. Do not select the Mirror Displays tick box (unless you want the second screen to show the same content as your original screen).

  5. Drag the illustrated displays into the arrangement you require. A white menu will be shown on the main screen (although since the launch of OS X Mavericks all screens can have a menu bar). Drag this white bar to the screen you wish to be dominant.

Comments:

  • If you want to mirror the display on both (or multiple) displays go to System Preferences > Displays > Arrangement and choose Mirror Displays.

  • You can also select 'Show mirroring options in the menu bar when available' and you will see a status menu in the menu bar making it easier to turn this off and on again.

The 27-inch LG UltraFine 5K Display features a 5120 x 2880 resolution, a P3 color gamut, 500 cd/m2 of brightness and built-in stereo speakers, camera, and microphone. Integration with macOS lets you control your display's volume and brightness without the need for physical buttons on the display.

When you connect the display using a single Thunderbolt 3 cable (included), it provides up to 85W of charging power to your MacBook Pro with Thunderbolt 3 (USB-C) ports. The display has three downstream USB-C ports (5 Gbps) that offer additional connectivity and power to compatible devices and accessories.


System requirements and compatible Mac models

The LG UltraFine 5K Display requires a compatible Mac running macOS Sierra 10.12.1 or later (macOS Sierra 10.12.2 or later is recommended). Compatible Mac models are grouped below by the resolutions that they support.

5120 x 2880 @ 60Hz

You can use the LG UltraFine 5K Display with these Mac models at full 5K resolution:

  • iMac Pro (2017)

  • iMac (2017)

  • Mac mini (2018)

  • MacBook Pro (2016 and later)

  • MacBook Air (Retina, 13-inch, 2018)


3840 x 2160 @ 60Hz

With the Apple Thunderbolt 3 (USB-C) to Thunderbolt 2 Adapter and a Thunderbolt cable, you can use the LG UltraFine 5K Display at 4K and lower resolutions with these Mac models:

  • Mac Pro (Late 2013)

  • MacBook Pro (Retina, 15-inch) 2014 and 2015

  • MacBook Pro (Retina, 13-inch) 2014 and 2015

  • iMac (Retina, 27-inch) 2014 and 2015

  • iMac (Retina, 21.5-inch, Late 2015)

  • iMac (21.5-inch, Late 2015)

  • MacBook Air (13-inch, Early 2015)

  • MacBook Air (11-inch, Early 2015)


USB-C power delivery

The LG UltraFine 5K Display provides up to 85W of power over USB-C and will fully power MacBook Pro (2016 and later) and MacBook Air (Retina, 13-inch, 2018) using the included Thunderbolt 3 (USB-C) cable.

Power isn't delivered from the display to your Mac when you connect with the Apple Thunderbolt 3 (USB-C) to Thunderbolt 2 adapter. If you're using this adapter, you need to also connect your Mac to power using the power supply it came with.

The LG UltraFine 5K Display provides 7.5W to each of its three downstream USB-C (5 Gbps) ports. To charge Apple Lightning-based devices and accessories — such as iPhone, iPad, AirPods, Magic Keyboard, Magic Trackpad 2, and Magic Mouse 2 — you can use the Apple USB-C to Lightning Cable or a combination of the Apple USB-C to USB Adapter and the Apple Lightning to USB Cable.


If you have issues connecting the display

  • If you don't see an image after connecting the LG UltraFine 5K Display to your Thunderbolt 3-equipped Mac, make sure that you're using the cable that came with the display. If you don't have it, you can use a Thunderbolt 3 cable capable of delivering 5A of power.

  • The LG UltraFine 5K Display doesn't support daisy-chaining of Thunderbolt 3 devices or displays. The three USB-C ports on the display provide additional connectivity to USB 3 devices only.

  • You can download the LG UltraFine 5K Display owner's manual and LG Screen Manager software on the LG Manuals & Documents page. Firmware updates for the LG UltraFine display are managed using LG Screen Manager. Run it periodically to check for and install firmware updates.

The 21.5-inch LG UltraFine 4K Display features a 4096 x 2304 resolution, a P3 color gamut, 500 cd/m2 of brightness and built-in stereo speakers. Integration with macOS lets you control your display's volume and brightness without the need for physical buttons on the display.

When you connect the display using a single USB-C cable (included), it provides up to 60W of charging power to your MacBook, MacBook Air, or 13-inch MacBook Pro. The display has three downstream USB-C ports (480 Mbps) that offer additional connectivity and power to compatible devices and accessories.


System requirements and compatible Mac models

The LG UltraFine 4K Display requires a Mac with one or more USB-C ports, running macOS Sierra 10.12.1 or later (macOS Sierra 10.12.2 or later is recommended).

4096 x 2304 @ 60Hz

You can use the LG UltraFine 5K Display with these Mac models at full 4K resolution:

  • iMac Pro (2017)

  • iMac (2017)

  • Mac mini (2018)

  • MacBook Pro (2016 and later)

  • MacBook Air (Retina, 13-inch, 2018)

  • MacBook (2016 and later)


4096 x 2304 @ 48Hz

  • MacBook (Retina, 12-inch, Early 2015)

A Mac with built-in USB-C or Thunderbolt 3 (USB-C) ports is required; the display isn't compatible with Mac models that use Thunderbolt 2.


USB-C power delivery

The LG UltraFine 4K Display provides up to 60W of power over USB-C and can fully power these Mac models using the included USB-C cable:

  • MacBook Pro (13-inch, 2016 and later)

  • MacBook Air (Retina, 13-inch, 2018)

  • MacBook (2015 and later)

The UltraFine 4K won't fully power 15-inch MacBook Pro from 2016 and later, which requires 85W. If you try to power your 15-inch MacBook Pro through the display, your notebook's battery will be utilized during times of heavy activity. To fully power your MacBook Pro and charge its battery, connect your 15-inch MacBook Pro to its Apple 87W USB-C power adapter when you use it with the UltraFine 4K.

 

The LG UltraFine 4K Display provides 7.5W to each of its three downstream USB-C (480 Mbps) ports. To charge Apple Lightning-based devices and accessories — such as iPhone, iPad, AirPods, Magic Keyboard, Magic Trackpad 2, and Magic Mouse 2 — you can use the Apple USB-C to Lightning Cable or a combination of the Apple USB-C to USB Adapter and the Apple Lightning to USB Cable.

 


If you have issues connecting the display

  • If you don't see an image after connecting the LG UltraFine 4K Display to your Mac, make sure that you're using the cable that came with the display. If you don't have it, you can use a USB-C 3.1 cable such as the Belkin 3.1 USB-C to USB-C Cable.

  • You can download the LG UltraFine 5K Display owner's manual and LG Screen Manager software on the LG Manuals & Documents page. Firmware updates for the LG UltraFine display are managed using LG Screen Manager. Run it periodically to check for and install firmware updates.

The adapter you require depends on the model of Mac and the type of monitor. Apple has implemented quite a few different port types over the years, and your iMac or MacBook might feature any of the following.

Note: You can buy adapters from a number of third parties, and they may well be cheaper than Apple's offerings. However, it appears that since Apple unleashed macOS Sierra some of these third-party adapters may no longer work.


Mini-Display Mini DisplayPort

Mini DisplayPort was announced by Apple towards the end of 2008. With an adapter, the Mini DisplayPort can drive displays that feature VGA, DVI or HDMI interfaces. This is what Mini DisplayPort looks like.


Thunderbolt Thunderbolt

The Thunderbolt port, first introduced in 2011, looks the same as Mini DisplayPort (and is backwards-compatible). If you see a thunderbolt symbol besides what looks like a Mini DisplayPort, your Mac has a Thunderbolt port. You can use a Mini DisplayPort adapter in a Thunderbolt port but you can also use Apple's Thunderbolt to Gigabit Ethernet Adapter or Thunderbolt to FireWire Adapter with it. A Thunderbolt-equipped Mac can connect a 4K Ultra HD TV via a direct HDMI connection, or via a Thunderbolt to high-speed HDMI adapter. In 2013 Apple introduced Thunderbolt 2, which is faster than Thunderbolt 1, but the port is the same.


USB type C Thunderbolt 3 or USB-C

From around the end of 2016 Apple started equipping its higher-end systems with Thunderbolt 3, which connects devices to your computer at up to 40Gbps. The connection looks the same as USB-C. Unfortunately, if you were hoping to plug your new MacBook Pro into a second display you may be out of luck as the Macs that use Thunderbolt 3 or USB-C won't work with any of the following adapters, even if you use a Thunderbolt 3 (USB-C) to Thunderbolt 2 Adapter.

  • Apple Mini DisplayPort to Dual-Link DVI Adapter

  • Apple Mini DisplayPort to DVI Adapter

  • Apple Mini DisplayPort to VGA Adapter

  • Apple LED Cinema Display


VGA VGA

A VGA connector requires a three-row 15-pin DE-15 connector. VGA connectors transmit analogue signals. Old CRT (Cathode Ray Tube) monitors were VGA but there are flat displays that use VGA - they just convert the VGA connector's analog signal back to digital. This conversion from digital to analog and back again can cause degradation of video quality. VGA will carry HD video but only analogue audio.


DVI DVI

DVI offers a higher-quality signal than VGA because it's a digital signal. You will see a marked difference when looking at HD video as compared to VGA. A DVI connector has the potential for 24 pins, depending on whether it's DVI-A, DVI-D or DVI-I, there are different connectors with a different number of pins in use. There is also a long pin which may be surrounded by four other pins (which are required for audio in older models). Apple's Mini DisplayPort to DVI Adapter has holes for all 24 pins but not the four pins that surround the long pin.


HDMI HDMI

The main difference between DVI and HDMI is that HDMI supports up to eight channels of audio, while DVI supports video only. HDMI 2.1 brings support for resolutions up to 8k and higher. HDMI is the most common connector you'll find on the back of a TV.

You can resolve many display issues by updating the software on your Apple devices, cables, and adapters. If you can see an image on your screen, check for software updates using the Mac App Store:

  1. Connect your external display and any Apple video cables or adapters that you use with it.

  2. From the Apple menu, choose App Store.

  3. Click the Updates button in the App Store window.

  4. Install any macOS or firmware updates that are listed.

If you're using a display, hub, extender, or adapter not made by Apple, check with the manufacturer for any updates that might be available.

If you're trying to connect a 4K display or Ultra HD TV with your Mac, make sure your computer meets the requirements for using these external displays.

If your software and firmware are up to date, or if you can't see the image on your screen, try the steps below for your specific issue.

Try these steps if you don't see an image on your display. These steps can also help if the image on your screen repeatedly turns on and off (flickers), if horizontal lines appear (snow), or if the image is distorted (torn or scrambled). These steps likely won't help if the issue is only happening in one app. If you see similar issues in only one window or app, check with the app's developer for updates or more help.


Check connections

  • If you're using an Apple notebook, try connecting its power adapter.

  • Make sure the external display's power cable is securely connected and that your display is turned on.

  • If you're using a Mac Pro (Late 2013) make sure your displays are connected to the right ports.

  • If you're using a display hub, switchbox, or "KVM," try connecting your display's video cable directly to your Mac instead.

  • Disconnect the video cable where it plugs into your Mac, then plug it back in to reseat the connection.

  • If you're using a video adapter, unplug the video adapter from your Mac, then plug it back in to reseat the connection.

  • If you're using more than one video adapter to connect your display (the adapters are "chained" together), try connecting the display using only one adapter if possible. Some video adapters can't be connected together. For example, a mini DisplayPort to DVI adapter can't be connected to a DVI to HDMI adapter.

  • If your display has more than one video connection, see if using another connection on the display works. If possible, check to see if using a different display or a different adapter works.

  • Try using a different cable that you know is in working order. Check with the display's manufacturer to make sure you're using the cable they recommend.

  • Restart the Mac with the display connected.


Detect your display

If you're using an external display, sleep and wake your Mac to make it check for connected displays:

  1. Press the power button on your computer to put it to sleep, or choose Apple menu > Sleep.

  2. Wait a few moments, then press a key on your keyboard or click your mouse or trackpad to wake your Mac.


Adjust video settings

f there's no image on your display, try adjusting your display's brightness or contrast. If there's still no image, or the image appears torn or scrambled, try selecting a different video resolution in System Preferences.

Adjust brightness

  • If you're using an Apple Display, press the increase brightness key F2 key image on your Apple keyboard. To adjust the brightness of a secondary display, press Control-F2.

  • If you're using a display that's not made by Apple, check the documentation that came with your display to see if it includes built-in controls for adjusting its brightness or contrast.

If images or text on your display appear pixelated or blurry, check these things.

Check your display resolution

Make sure your display resolution in System Preferences is set to its default. If you're using a resolution that's scaled, the image might be magnified to fit the display. This can cause the image to look blurry in some apps.

  1. From the Apple menu, choose System Preferences.

  2. Click the Displays icon.

  3. Select Default for display.

If you use a monitor or an HDTV connected with an HDMI cable, you might see a difference in video quality if your display is set to television mode. Check your display for a "monitor mode" setting to get the best video quality.

If your entire display image seems too dark or too bright, you can adjust the brightness and contrast from the Displays pane of System Preferences, or by using your display's built-in controls.

Adjust brightness and contrast

To adjust the brightness of your Apple display, press the brightness key (F2 key) on your keyboard. You can also use the brightness adjustment for each connected display in System Preferences > Displays. Displays not made by Apple sometimes have brightness and color adjustments built into the display. Check the documentation for your display to see if it includes built-in controls.

When you connect a display, projector, or HDTV using an HDMI cable, you might see a difference in video quality if your display is set to television mode. Check your device for a "monitor mode" setting to achieve the best video quality. You can also calibrate each display from the Color tab of Displays preferences to get the best color and brightness from your display.

The Apple Thunderbolt 3 (USB-C) to Thunderbolt 2 Adapter connects Mac models with Thunderbolt 3 (USB-C) ports to older devices that use Thunderbolt (10Gbps) or Thunderbolt 2 (20Gbps). For example, this is the adapter that you should use to connect your MacBook Pro to an Apple Thunderbolt Display or a third-party Thunderbolt 2 storage device.

This adapter doesn't support connections to Mini DisplayPort displays, including the following Apple adapters and displays:

  • Apple Mini DisplayPort to Dual-Link DVI Adapter
  • Apple Mini DisplayPort to DVI Adapter
  • Apple Mini DisplayPort to VGA Adapterv
  • Apple LED Cinema Display

If you're using the Thunderbolt 3 (USB-C) to Thunderbolt 2 Adapter to connect to a compatible display and the display doesn't show an image, try unplugging the adapter and plugging it back in.


External display is not working with a Mini DisplayPort adapter

If your adapter is not made by Apple, that might just be the issue here. Prior to macOS Sierra it was possible to use a third-party Mini DisplayPort to DVI adapter with a Mac, but since Sierra launched Mac users who were reliant on that setup have found their monitors have stopped working with their Mac. The only solution if this is the case is to purchase an Apple adapter. If you have an Apple adapter and your external display isn't working, try the following:

  1. Disconnect your adapter for a few seconds.

  2. Reconnect it and see if the issue persists.

  3. Disconnect the adapter again and power off the monitor.

  4. If it's still not working, connect the cable again and power off the display.

  5. If when you turn the display back on it's still not working, click on the Apple logo and choose Sleep.

  6. Wait a few minutes and then move your mouse or tap your keyboard to wake your Mac.

  7. If that doesn't work, restart the computer.

  8. Try adjusting the display's brightness or contrast just in case it's turned down.

  9. Go to System Preferences > Display and try selecting a different resolution.

  10. If that still doesn't work, try restarting your Mac in safe mode and then reset the display resolution to defaults.

  11. Another option is to reset the Mac's NVRAM and SMC.


Mac won't detect the external display

When you connect your display and your Mac the display should automatically be detected. But what should you do if it isn't? As we explain above, if your adapter is not made by Apple that might just be the issue here. If you are using an Apple adapter, try the following:

  1. Connect your monitor and Mac and open System Preferences > Displays.

  2. Press the Alt/option key. This should make the Detect Displays button appear.

  3. Click on Detect Displays. This should cause your Mac to see the external monitor.


DVI adapter doesn't fit in the connection

There are a few possible reasons why the Apple Mini DisplayPort to DVI adapter might not be compatible with your monitor. There is more than one kind of DVI adapter and the likelihood is the one you have is different to the adapter you are using. For example, you may require space for four analog ports around the flat blade. If your problem is that you have two female or two male connections then the solution is to buy a male-to-female adapter. Cable too small between the two devices? You should be able to hook up your adapter to the screen via a third-party cable. Just make sure it has the correct port type.


How to connect a Thunderbolt 3 MacBook Pro

You can use the Apple Thunderbolt 3 (USB-C) to Thunderbolt 2 Adapter to connect a 2016 or later MacBook Pro with Thunderbolt 3 (USB-C) ports to a Thunderbolt display, but what if you haven't got a Thunderbolt display? To connect to a DVI display you need a USB-C to DVI cable or adapter and Apple doesn't make one. You may be able to find one, but we can't guarantee that it will work as it appears third-party adapters do not work with Macs that have been updated to macOS Sierra and later. Similarly Apple doesn't make a USB-C to Mini DisplayPort adapter, so you won't be able to connect a 2016 or later MacBook Pro to the Apple Cinema Display which uses a Mini Display Port and as such is not compatible with the MacBook Pro.


How to connect a third monitor to a Mac

Theoretically you shouldn't be able to attach a monitor to a USB port, but a few companies have treated this as a technical challenge. The Matrox DualHead2Go and TripleHead2Go let you connect up to two or three external displays respectively. They do this by augmenting the standard DVI/HDMI video output of a Mac or PC with data provided via a USB 2.0/3.0 connection. To learn if your Mac is compatible, check out Matrox's Mac compatibility listing, where you'll also learn the maximum possible output resolutions - it's unlikely you'll be able to run all three displays at 1080p, for example.

Diamond MultiMedia's BVU range lets you run a separate external display via nothing more than a USB 2.0 port. By connecting one to a MacBook Pro, as one example, you could utilize up to three displays: one built in, one via the existing DVI/HDMI/DisplayPort, and one more via USB. There are also some no-brand devices on eBay and Amazon that offer the same functions as the Diamond product, and are cheaper to boot - although be sure to check for Mac compatibility. Just search for something like USB to DVI HDMI.

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