Thunderbolt Display Issue Not Displaying Before Log In

[Blue Hour]

Hello All,

I'm having issue with my Thunderbolt Display. I'm 99% sure it's software/setting related so I'm not sure if I'm posting this in the correct place.

Display is currently set to mirror my Macbook and displays the login screen and desktop with no issues.

It doesn't display anything up until the log in screen. I'm not sure if this is normal but it is not normal for me. For example holding down alt/option to select the boot drive or installing/reinstalling OS X. This isn't displayed on screen it was before. When I try to reinstall OS X I just get a grey screen on the TBD.

I've done a complete (clean) reinstall erasing the hard disk and reinstall from the restore and from USB. I've spoken to Apple they tell me this is normal behaviour for a TBD but it can't be as my display has shown installs and the start up disks since I got it I have no idea what has changed.

Thank you very much for your time.

Regards,

Blue

 

[FreakinEurekan]

I've spoken to Apple they tell me this is normal behaviour for a TBD but it can't be as my display has shown installs and the start up disks since I got it I have no idea what has changed.

Perhaps your system was behaving abnormally before?

I use Extended Desktop but just did some testing with 3 computers (iMac, MacBook Air, and Mac Mini) with dual displays and set them to Mirroring - none of them show anything on the 2nd display until the login screen; they don't show anything on the 2nd display during option-boot.

The behavior you're seeing now seems perfectly normal to me. All my machines are running Mavericks; I suppose it's possible behavior in the past was different but I never used Mirroring - only extended desktop - so couldn't say.

 

[Blue Hour]

Perhaps your system was behaving abnormally before?

I use Extended Desktop but just did some testing with 3 computers (iMac, MacBook Air, and Mac Mini) with dual displays and set them to Mirroring - none of them show anything on the 2nd display until the login screen; they don't show anything on the 2nd display during option-boot.

The behavior you're seeing now seems perfectly normal to me. All my machines are running Mavericks; I suppose it's possible behavior in the past was different but I never used Mirroring - only extended desktop - so couldn't say.

Thank you very much for your time I appreciate the time you've taken to run the tests for me and to reply.

I am reassured that the behaviour seems normal on your display. However it still bothers me I have been running my Macbook mostly in "claim shell" when at home. I have never had to open it before now to see anything prior to the loading screen.

One thing I have noticed is it used to turn on quicker it used to show a white screen at the chime and then the Apple logo would appear. Now the first sign of life on my TBD is the Apple logo.

I went through my recent updates with Apple support and they said although it does not describe my issues the recent EFI boot update may have caused it. I have no idea what that is so can't say.

Either way I thank you for your time it has helped put my mind at ease. Even if I'm still bothered a little and would like to "fix" this problem.

 

[FreakinEurekan]

I have been running my Macbook mostly in "claim shell" when at home

Clamshell mode is a whole other story. You definitely should be seeing the Option-startup menu and any other pre-login screen displays in Clamshell mode. But if your MacBook lid is open, those screens will only show on the built-in display.

If it's not displaying properly in clamshell mode, ensure that you have external power, and external keyboard/mouse/trackpad connected. These are prerequisites for Clamshell to work right.