Chosen Solution
I have a similar issue to Sometimes, main display only work when connected to external monitor, except with an early 2015 13" MacBook Pro, for which I don’t have the option to disable the graphic switching. At the moment, my solution is to maintain a dummy hdmi emulator plugged in at all times. Is there any software workaround, such as disabling a driver or so ? Note that the problem also goes away when booting in safe mode (but then I lose the audio). Thanks Update (07/07/2022) My model is early 2015, 13" retina, with Intel Iris Graphics 6100. Given that booting in safe mode “solves” the issue, doesn’t it mean that there could be a way to boot in normal mode while mimicking what safe mode is doing regarding display ?
@sorhuet Your system is no different from the 15" IG model. I wish I could offer you a better solution there just isn’t any you have a hardware level problem within the MUX logic and how the signal is terminated between the different external ports. This is all within the logic board, and you’ll need someone with the deeper skills to fix it or just live with the dummy load setup as others have. Safe mode doesn’t help you, it is a firmware video driver, which is why it appears to work! Safe Mode is useful to diagnose OS and some software level issues it is not intended to run as many of the needed software drivers are not loaded which are OS based.
