Chosen Solution
Try to use my 2009 iMac 27” desktop as an external monitor, but can’t get the target displaying mode working, when connecting with the MacBook Pro 15” through mini-display port cable, the screen just flash into black, then back to itself again, samething when pressing command and F2. Any ideas why the target displaying mode not functioning? Thanks, Alex
Review these: The Ins And Outs Of Your IMac’s Target Display ModeUse your iMac as a display with target display mode Make sure you are using the proper cable as some configurations won’t work if you use the wrong cable (iDP vs TB as well as the generation of TB)
