User profile for user: jakerfl2010
jakerfl2010 Author
User level: Level 1
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Mid 2012 Macbook Pro Can't Connect to Two External Monitors

As the title says I have a Mid 2012 MBP and cannot get it to connect successfully two external monitors i just purchased. One of the monitors will connect. I have a mini display port to HDMI adapter connected to one of the monitors. I have tried a few things

-I bought a USB to HDMI adapter and tried to plug it into the other with no luck

-I then bought a VGA cable and connected both the VGA ports on the back of the monitors together while having the monitor that was working connected. The second monitor still did not detect a signal


There is nothing wrong with the other monitor. I have disconnected the monitor currently set up and connected the other one with the mini display port to HDMI adapter and it worked fine and connected. I just cant get both monitors to connect at the same time.


Both monitors have HDMI and VGA inputs. The monitors are the exact same (HP VH240a). I have tried restarting and disconnecting everything with no luck either.


Any help is much appreciated.


Thanks!

Jake

MacBook Pro (13-inch Mid 2012)

Posted on Aug 15, 2018 5:27 PM

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User profile for user: Grant Bennet-Alder
Grant Bennet-Alder
User level: Level 10
140,867 points

Posted on Aug 16, 2018 7:17 AM

Neither the 13-in nor the 15-in MacBook Pro from 2012 natively support more than one external display. There is no additional Hardware inside to support more.


To support two External displays at full-motion Video speeds, you need more computer.


There are some docks and adapters than can simulate an additional display. They do this by loading software that creates an additional screen buffer in RAM, then sends the un-accelerated display data out over a more mundane interface like USB, to a stunt-box. The stunt-box contains chips that can convert that data onto a "real" interface, to run a real display. However, the lag involved makes full motion video impossible, and mouse-tracking somewhat uncomfortable for some users.


All these chips and software solutions, regardless of the brand they are sold under, appear to be made by DisplayLink, and require the installation of its software only (un-accelerated) Driver. If you need Extended Desktop or Mirroring, you need to know that DisplayLink has reported their software cannot support those features in High Sierra, 10.13.5 and later, due to security changes Apple made in the system.


NewerTech USB 3.0 to DVI Video Adapter From OWC

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User profile for user: Grant Bennet-Alder
Grant Bennet-Alder
User level: Level 10
140,867 points

Aug 16, 2018 7:17 AM in response to jakerfl2010

Neither the 13-in nor the 15-in MacBook Pro from 2012 natively support more than one external display. There is no additional Hardware inside to support more.


To support two External displays at full-motion Video speeds, you need more computer.


There are some docks and adapters than can simulate an additional display. They do this by loading software that creates an additional screen buffer in RAM, then sends the un-accelerated display data out over a more mundane interface like USB, to a stunt-box. The stunt-box contains chips that can convert that data onto a "real" interface, to run a real display. However, the lag involved makes full motion video impossible, and mouse-tracking somewhat uncomfortable for some users.


All these chips and software solutions, regardless of the brand they are sold under, appear to be made by DisplayLink, and require the installation of its software only (un-accelerated) Driver. If you need Extended Desktop or Mirroring, you need to know that DisplayLink has reported their software cannot support those features in High Sierra, 10.13.5 and later, due to security changes Apple made in the system.


NewerTech USB 3.0 to DVI Video Adapter From OWC

.

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Mid 2012 Macbook Pro Can't Connect to Two External Monitors

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