On My Imac 27 Late 2015 1 2 Led Are On Display Is Disconnected Imac Intel 27 Retina 5K Display
Chosen Solution Hi. On my iMac 27’’ Late 2015 LED#1 and LED#2 are ON (display is disconnected) and the fan starts spinning very fast after boot (the Mac makes the sound when turning on). Also you can hear a faint sizzling sound coming from the power supply before the fan starts to ramp up (because then it drowns all other noise). The computer has been acting up the past couple of weeks, sometimes not turning on, sometimes turning on with the fans at max speed, sometimes turning off suddenly after a while....