iMac won't start with Thunderbolt Display connected after firmware update

Hello rameta,

It may help to reset your Mac's SMC and PRAM.

Intel-based Macs: Resetting the System Management Controller (SMC)

http://support.apple.com/kb/HT3964

Reset your computer’s PRAM

http://support.apple.com/kb/HT1379

Cheers,

Allen

I'm having the same problem with my macbook pro late 2013, since the update it won't boot unless i unplug the display

Thanks allen a but your suggestions doesn't work on my MacBook which is experiencing the same issue related by rameta.

After reseting SMC an PRAM I still have to unplug my Tbolt 27" display to start Up.

Any more idea from anybody?

MacBook Pro 15" Mid 2014 Yosemite 10.10.2 (14C109)

Disconnect the TBD from your Mac. Then unplug the TBD from the wall. Wait 2 minutes then reconnect everything and test.

Hi tbirdvet,

Unplugged all, wait two minutes, plugged all again, I repeated the procedure twice... but no results. I still have to unplug the TBD to get my MacBook started Up

Thanks for the try, though

Having the same issue. I've tried the fixes listed, all to no avail.

Hi Allen,

I am having this exact problem with my iMac (Retina 4K 21.5 " late 2015, 3.3 Ghz Intel Core i7, El Capitan 10.11.5) and ASUS VH222H monitor. I see this thread started in Nov. 2014, and here it is, May 2016 and the problem still has not been solved. I too have tried your solution, and spent an hour on the phone with Apple support. With my previous iMac (late 2009) I never had this problem, and it was running El Capitan 10.11.2 or 3).

As a "community specialist" do you have ways of alerting Apple to problems unavailable to the rest of us?

Thanks for your help!

I'm having the same problem with my MacbookPro (13" Early 2015, Intel Iris Graphics 6100, running El Capitan 10.11.4). I am connecting to a Dell 2715H external monitor using a mini-display port to Display port connector. When I startup, if the Mini-display port cable is connected, the Macbook will begin to start up, the white bar gets about half-way across, then everything goes black. If I force a restart and unplug the cable, the Macbook comes up fine. I log in, and then plug in the external monitor -- then everything is perfect. This is happening at work and at home, on two different monitors, using two different cables, so this does appear to be related to the Mac.

I'm having the same issue with a 2015 Macbook Air.