I have an old Macbook Pro 17" that I still use whenever I need to work away from the office. It has been running on High Sierra for quite some time now, without problems whatsoever.
Yesterday I installed a 'security update'. That is to say, I started the update and walked away. When I came back two hours later the computer was trying to lift off (fans blowing full force), on the screen was the apple logo and a progress-bar filled to 90%. I turned off the Mac, and when I rebooted I got as far as the Apple logo with a progress-bar beginning to fill up but then immediately the screen goes black and the computer reboots. First I thought maybe a firmware update is being done, but after four reboots I shut down the computer and rebooted in recovery. Disk utility found nothing wrong with the disk, so I turned it off again, did a SMC reset and rebooted with alt-cmd-R-P to reset the VRAM. No luck, still a continuous reboot.
I then rebooted again in recovery, re-installed the system, did the whole reset-sequence agin but still the same.
I figured some left-over kext or something messed up the computer, so I attached an external drive and did a clean install on that (after a cloud-recovery-reboot). But when starting up from this drive it still does the reboot loop.
Fearing a hardware problem I then installed Sierra on an external disk. And voila, the computer starts up without any problems.
So... It appears somewhere in the latest version of High Sierra there is something that my computer dislikes. I tried to start in Single-user-mode to see what causes the reboot, but it goes all too fast to even read what is on screen before the reboot happens...
I read about problems with the dGPU, but I can boot in recovery without problems, and as I understand it from what I read that would not be possible if my dGPU was faulty... FWIW, just before the security update messed things up, I had an external display attached. This would also be impossible if the dGPU was not working.
Is there any way I can find what is causing the problem? Most solutions I can find involve installing software (like Etrecheck which I found very handy in the past), but since I have no access to a running computer in High Sierra that is not an option. From what I gather during my Google sessions it is likely a conflicting kext, but which one??
I am reasonably handy with the terminal, so if there is a log file somewhere to read I would like to know. But /var/log appears to be empty, apart from two empty directories (asl and com.apple.xpc.launchd).
Tnx
Yesterday I installed a 'security update'. That is to say, I started the update and walked away. When I came back two hours later the computer was trying to lift off (fans blowing full force), on the screen was the apple logo and a progress-bar filled to 90%. I turned off the Mac, and when I rebooted I got as far as the Apple logo with a progress-bar beginning to fill up but then immediately the screen goes black and the computer reboots. First I thought maybe a firmware update is being done, but after four reboots I shut down the computer and rebooted in recovery. Disk utility found nothing wrong with the disk, so I turned it off again, did a SMC reset and rebooted with alt-cmd-R-P to reset the VRAM. No luck, still a continuous reboot.
I then rebooted again in recovery, re-installed the system, did the whole reset-sequence agin but still the same.
I figured some left-over kext or something messed up the computer, so I attached an external drive and did a clean install on that (after a cloud-recovery-reboot). But when starting up from this drive it still does the reboot loop.
Fearing a hardware problem I then installed Sierra on an external disk. And voila, the computer starts up without any problems.
So... It appears somewhere in the latest version of High Sierra there is something that my computer dislikes. I tried to start in Single-user-mode to see what causes the reboot, but it goes all too fast to even read what is on screen before the reboot happens...
I read about problems with the dGPU, but I can boot in recovery without problems, and as I understand it from what I read that would not be possible if my dGPU was faulty... FWIW, just before the security update messed things up, I had an external display attached. This would also be impossible if the dGPU was not working.
Is there any way I can find what is causing the problem? Most solutions I can find involve installing software (like Etrecheck which I found very handy in the past), but since I have no access to a running computer in High Sierra that is not an option. From what I gather during my Google sessions it is likely a conflicting kext, but which one??
I am reasonably handy with the terminal, so if there is a log file somewhere to read I would like to know. But /var/log appears to be empty, apart from two empty directories (asl and com.apple.xpc.launchd).
Tnx
