- Jul 1, 2017
Right. The before image shows the defective dGPU trying to boot the system. The after image displays the result of having forced the iGPU to handle the display in the gpu-power-prefs command. But this is only step one of the process.
Using nsgr's findings, GBDO created a guide to doing the whole job. The trick is to remove a critical driver, AMDRadeonX3000.kext from it's default location folder /System/Library/Extensions and moving (hide) it to a folder you create called backup. the boot process then cannot find the driver to reload the defective AMD graphics chip that you saw in your 'before' image.
The AMDRadeonX3000.kext is still required however to reduce power to the now unused dGPU and reduce current being drawn by the the dGPU and overheating the motherboard. The trick is to load this driver with Terminal AFTER login and the gpu-power prefs settings have been changed to use the iGPU all the time.
You might like to have a look at post #429 where GDBO documented a step by step guide using nsgr's findings...