Login window (on boot) shown on wrong monitor

[dannyg86]

I have a problem with Yosemite that I never previously had with Mavericks.

I connect my mac to an external monitor (via thunderbolt) and use this monitor to use my mac (i don't use the iMac screen). I do this because I share the monitor, keyboards etc via a KVM switch.

On Mavericks, the login screen either displayed on my external monitor, or both. I have mirroring set up so the mouse doesn't go over to the iMac screen (the iMac is out of viewing distance).

Now on Yosemite, the login screen only ever shows on the iMac. It occasionally shows on the external monitor, but 9.9 times out of 10 it displays on the iMac only.

Has anyone else encountered this, and if so, have you found a resolution?

Thanks in advance.

 

[redsquash]

I have a problem with Yosemite that I never previously had with Mavericks.

I connect my mac to an external monitor (via thunderbolt) and use this monitor to use my mac (i don't use the iMac screen). I do this because I share the monitor, keyboards etc via a KVM switch.

On Mavericks, the login screen either displayed on my external monitor, or both. I have mirroring set up so the mouse doesn't go over to the iMac screen (the iMac is out of viewing distance).

Now on Yosemite, the login screen only ever shows on the iMac. It occasionally shows on the external monitor, but 9.9 times out of 10 it displays on the iMac only.

Has anyone else encountered this, and if so, have you found a resolution?

Thanks in advance.

I have mirroring ticked , but when the icons come up to log into my 27 inch imac, the 21inch monitor is not not mirrored The cursor can be seen to transition from one screen far right to the smaller screen,far left, if I move it so.
After logging in , both screens are identical. !!!!!!!!!!!!!!!!!!!!!!!!!!
please help

 

[Marcwil]

Similar Issue With Wrong Monitor on Boot

I have a similar issue; on boot up with login required, my external monitor is not useful. The image is blurred out (Extreme "Vibrancy".) and I can't log in. I have to go to the MBP inside my desk cabinet to log in from the laptop keyboard. This just started with Yosemite, so I don't know if it's behavior change or if I have missed a setting somewhere.

 

[redsquash]

I have mirroring ticked , but when the icons come up to log into my 27 inch imac, the 21inch monitor is not not mirrored The cursor can be seen to transition from one screen far right to the smaller screen,far left, if I move it so.
After logging in , both screens are identical. !!!!!!!!!!!!!!!!!!!!!!!!!!
please help

The problem hasn't dissappeaed but a work around is by going into system preferences/security and privacy /and ticking automatic login under the genral tab I can get both screens to operate

 

[redsquash]

I have mirroring ticked , but when the icons come up to log into my 27 inch imac, the 21inch monitor is not not mirrored The cursor can be seen to transition from one screen far right to the smaller screen,far left, if I move it so.
After logging in , both screens are identical. !!!!!!!!!!!!!!!!!!!!!!!!!!
please help

The problem hasn't dissappeaed but a work around is by going into system preferences/security and privacy /and ticking automatic login under the genral tab I can get both screens to operate

 

[LevMac]

Does anyone know if this issue has been fixed with the latest beta 10.10.1 update?

 

[Azzin]

I have a similar issue; on boot up with login required, my external monitor is not useful. The image is blurred out (Extreme "Vibrancy".) and I can't log in. I have to go to the MBP inside my desk cabinet to log in from the laptop keyboard. This just started with Yosemite, so I don't know if it's behavior change or if I have missed a setting somewhere.

I have the same issue: https://forums.macrumors.com/threads/1814728/

 

[LevMac]

Hey guys, has anyone tested with 10.10.2 to see if this problem has been resolved?

 

[LevMac]

Hey guys, has anyone tested with 10.10.2 to see if this problem has been resolved?

I cannot seem to work this one out!
The latest 10.10.5 hasn't fixed this either
I have my 15" MacBook Pro connected to my 27" Cinema Display, I've set my Cinema Display as my primary monitor, yet the log in screen only appears on my MacBook Pro when it should appear on the Cinema Display. After I put my password in, the main screen does become my Cinema Display, but it's just the log in screen which doesn't appear on the main monitor