Hello all and thank in advance!
I have followed LangLangC’s process in GPU problem - Boot Hangs on Grey Screen which was seemed a miracle after Apple said my graphics card was fried and there was nothing to do but replace the logic board. I have a couple hang ups though I don’t see anyone else discussing.
The fix doesn’t survive rebooting. Post reboot I have the exact same symptoms again. After repeating the entire cycle multiple times I tried only changing the power prefs (along with verbose mode and csrutil still disabled) and low and behold it rebooted, but every following reboot requires this or I get the same original symptoms.
Temperature is 60 degrees C minimum with no programs running and SMC at 4000 and sitting on an external fan board. I have tried his recommendations for improved power management with no success as noted below.
Notes(relative to LangLangC’s steps):
I had to do the GUI recovery mode to turn off csrutil
Trying to add back in RadeonX3000.kext to improve temp management after boot up yields “failed to load” because “not found” However, checking loaded .kexts EITHER before or after attempting to load X3000 shows that it is indeed present BUT AMDSupport which is listed as one of the critical files is missing (mine are 1.6.8’s rather than the 1.5.1’s in the post)
Turning off verbose mode as recommended for further improved temp control requires a reboot and thus sends the computer back into endless grey screen reboot cycle. I have to turn it back on along with power prefs changes to get it to boot
So it seems that despite following the steps meticulously and getting no errors until I try to add RadeonX3000 back after boot, I am either unsuccessful in removing RadeonX3000 and it was never the problem or it somehow gets back in.
Either way it is not helping the temp drop to the 15-50 C range as reported and an alternative “crucial” file for temp management is missing. (AMDSupport) And the only other options listed for dropping the temp is incompatible with my reboot behavior.
With symptoms returning on any reboot but being fixed by the NVRAM power pref changes I might assume that my NVRAM is getting reset on every reboot but I don’t see this discussed anywhere.
Has anyone else had these temp problems and reboot behavior after following these steps or have any insight?