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frankiee

macrumors regular
Original poster
May 31, 2008
198
94
I am in a really dire situation now, since I currently have a totally inaccessible Mac Pro.

This is what happened:

I installed the Big Sur Beta on an external SSD drive (after allowing external boot first). At first things went well, it took a while but then I heard that famous boot sound again and was into Big Sur. I played a while with it (did not like it too much) and then rebooted into Catalina. I wondered why that startup sound still was there, and it dawned on me that there might have been a firmware upgrade as well. But did not think too much about it first, went on to Catalina and disconnected the drive.

But then the problems started when I switched to my bootcamp install later on. At first I saw the windows logo, but then black screen ... then an automatic restart and then I landed in windows recovery. Uuuups! Then I choose to restart and then I got at least the windows login screen. But no reaction to anything, no mouse no keyboard. After while restart, into windows recovery again. (This at least seems to allow some interaction.)

And the thing is, directly after powering the machine on, I get this little spinner you can see if you switch from macOS to bootcamp via the control panel (which I initally did). In other words, no Apple logo. That also means, absolutely no reaction to the usual startup keys like alt, CMD+PR etc. So I also cannot change my startup OS to macOS back again, also no macOS recovery, just nothing but a constantly restarting windows. Since windows also does not allow me to login, I now effectively sit before a bricked machine. The only thing I could do is a reset/reinstall of windows, but not sure if this will lead me to anything, or make things even worse.

It just smells like there is a problem with the updated firmware (if it actually was updated, but the startup chime is still there, even in this state).

Any ideas? Any help is really really appreciated.
 

LuisN

macrumors 6502a
Mar 30, 2013
737
688
Torres Vedras, Portugal
I am in a really dire situation now, since I currently have a totally inaccessible Mac Pro.

This is what happened:

I installed the Big Sur Beta on an external SSD drive (after allowing external boot first). At first things went well, it took a while but then I heard that famous boot sound again and was into Big Sur. I played a while with it (did not like it too much) and then rebooted into Catalina. I wondered why that startup sound still was there, and it dawned on me that there might have been a firmware upgrade as well. But did not think too much about it first, went on to Catalina and disconnected the drive.

But then the problems started when I switched to my bootcamp install later on. At first I saw the windows logo, but then black screen ... then an automatic restart and then I landed in windows recovery. Uuuups! Then I choose to restart and then I got at least the windows login screen. But no reaction to anything, no mouse no keyboard. After while restart, into windows recovery again. (This at least seems to allow some interaction.)

And the thing is, directly after powering the machine on, I get this little spinner you can see if you switch from macOS to bootcamp via the control panel (which I initally did). In other words, no Apple logo. That also means, absolutely no reaction to the usual startup keys like alt, CMD+PR etc. So I also cannot change my startup OS to macOS back again, also no macOS recovery, just nothing but a constantly restarting windows. Since windows also does not allow me to login, I now effectively sit before a bricked machine. The only thing I could do is a reset/reinstall of windows, but not sure if this will lead me to anything, or make things even worse.

It just smells like there is a problem with the updated firmware (if it actually was updated, but the startup chime is still there, even in this state).

Any ideas? Any help is really really appreciated.
Try to reset PRAM. command+option+P+R keys at startup chime
 

frankiee

macrumors regular
Original poster
May 31, 2008
198
94
As I said, at least at first I had no way to issue CMD-OPT-P-R, CMD-R or getting to the boot manager by pressing ALT.

But, now I have regained control over the machine! Not sure what actually happended, I was just trying the various windows startup options, like safe mode, reduced resolution etc (none of them did work) but then, while being in windows recovery for the nth time, the machine suddenly just shut down. So no restart this time, just went away, something which never happened before. So I was like "ooooohh boy", but then, after booting up the machine again, the ALT key suddenly worked again and I was able to go the boot manager. Selected macOS and ... voila! Saw that the startup volume was still set to windows and of course quickly changed that to macOS again. But as it seemed the windows install still was broken.

Now, I also was able to get windows working again, simply by restoring windows from the last system restore point, using the recovery mode. I also saw a lot of spindumps and various temp + log files pointing to a corrupted windows installation.

Not sure if this was actually tied to that Big Sur firmware update, but it would be a quite big coincidence if my windows installation got corrupted _just_ after trying big sur, but with no connection to that. But who knows?

Nonetheless, now I actually want to revert that beta firmware to the version I had before. Is that actually possible? Because I still get this boot chime, and it is becoming increasingly annoying because it is so loud.
 

Fishrrman

macrumors Penryn
Feb 20, 2009
29,175
13,225
"Nonetheless, now I actually want to revert that beta firmware to the version I had before. Is that actually possible?"

I don't think that's possible -- at least "at the user level".
Firmware on the Mac is pretty much a "one-way" journey.

Apple may have a way to do this (I don't know).
But even if they do, they may not be willing to do it.

My assessment:
If things are "back the way they were before", just let them be.

Perhaps you ought to let Big Sur alone, for now.
 

simonmet

Cancelled
Sep 9, 2012
2,666
3,664
Sydney
Do you know holding Option on boot gives you the list of available startup drives?

No idea what might’ve happened to Boot Camp. I wouldn’t have thought it would be affected.

Also, you can enable/disable the Boot Chime in Catalina, so that’s not an issue, but a PRAM reset might stop it as well.
 

frankiee

macrumors regular
Original poster
May 31, 2008
198
94
Simonnet, did you actually read my post? Of course I know that key, but IT DID NOT WORK, at least for a while. And with a borked windows install in addition, there was no way out of this loop until it mysteriously worked again.

Yeah, I might be able to remove that boot chime, but my actual problem is that I now have a beta firmware, and I want to get rid of it. Also because right now, I plan to skip Big Sur entirely, since it is such almost painful to just look at (imho!).
 

simonmet

Cancelled
Sep 9, 2012
2,666
3,664
Sydney
It's not even public beta status yet. You took the risk. It's meant for developers who can handle having units temporarily out of action/borked, which you clearly cannot.

Good luck with it.
 
Last edited:

frankiee

macrumors regular
Original poster
May 31, 2008
198
94
Yeah, I am well aware that beta software can do weird things, this is exactly the reason why I have chosen an external drive to install and of course with everything backed up etc. I admit the possibility of updated firmware simply wasn't on my radar, but it really surprises me that this process is not reversible.

And the problems seem to continue, because just right now, the machine could not wake from sleep, with a subsequent KP report after restart that clearly points to a firmware issue ("Sleep Wake failure in EFI"). So I might have an unstable system from now on with no way to revert the situation? Yeah, thanks Apple.
 
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