No Video External Monitor Works If Main Screen Unplugged Imac Intel 27 Emc 2390
Chosen Solution I’ve got a 2009 27” iMac 1312 I get no video either externally or on the main screen. But if I unplug the ribbon cable from the main screen the external video works! Any ideas what it could be? Maybe logic board? The LCD was replaced 3 years ago. With the display removed locate the onboard diagnostic LED’s located at the bottom left edge near the RAM bay. There is a piece of black tape covering it....