PapaRayRay
New member
Unfortunately to hopefully provide all crucial data I have to quickly run it from the beginning 
(I'll try and give only highlights):
Came in from other shop for "only booting in safe mode" with a fresh install of Big Sur. I confirmed this issue with my eyes several times, tried a repair install which didn't happen because it struggled to boot to any bootable installer/OS; I set the computer aside for a day or two before getting to it. When I got to it- lo and behold: it magically worked properly, no issues at all; Big Sur in all its glory. It continued to work for about a week; turned it on and off and played YouTube etc. every day. After some failed SuperDuper clones from an older computer they wanted the clone from, we restore from a Time Machine backup of that older computer via Migration Assistant to a working fresh Catalina install. After restore back to only booting in safe mode. This time able to go to recovery and Catalina is available- repair install/data restore = SUCCESS WELP let's go to Big Sur! It ran through a "critical update" for like two minutes then went back to normal update. It got too late, left it alone after restart initialized, plugged in, updating. Came back in the morning. Now its worse. Now its a combination of, spazzes out chiming repeatedly for a lot of times then shuts off or it goes to load the apple then loops or just stays black; chiming every time. Not able to select a boot device, no recovery, no Diagnostics. I tried plugging in an external monitor because something I read on another post while making sure I'm not posting something that's already been posted here. I tried with/without battery, with/without power plugged in. It does except SMC and PRAM resets on the times that it’s not just “spazzing out,” but it doesn’t fix anything. Google/YouTube no help. I've repeatedly looked over the board under the microscope hoping to see something obvious, nothing catches my eye. I suspect EFI chip? But I'm aware I could be way off. I don't really know where to start poking around with the multimeter on this one or if its necessary.
I hope that's not too long and explains the issue clearly. I've never been a forum member anywhere I normally just read them, why? idk who cares. If there's anything I could do differently when presenting a topic that would benefit me and everyone who may share a problem, please let me know.
(I'll try and give only highlights):Came in from other shop for "only booting in safe mode" with a fresh install of Big Sur. I confirmed this issue with my eyes several times, tried a repair install which didn't happen because it struggled to boot to any bootable installer/OS; I set the computer aside for a day or two before getting to it. When I got to it- lo and behold: it magically worked properly, no issues at all; Big Sur in all its glory. It continued to work for about a week; turned it on and off and played YouTube etc. every day. After some failed SuperDuper clones from an older computer they wanted the clone from, we restore from a Time Machine backup of that older computer via Migration Assistant to a working fresh Catalina install. After restore back to only booting in safe mode. This time able to go to recovery and Catalina is available- repair install/data restore = SUCCESS
WELP let's go to Big Sur! It ran through a "critical update" for like two minutes then went back to normal update. It got too late, left it alone after restart initialized, plugged in, updating. Came back in the morning. Now its worse. Now its a combination of, spazzes out chiming repeatedly for a lot of times then shuts off or it goes to load the apple then loops or just stays black; chiming every time. Not able to select a boot device, no recovery, no Diagnostics. I tried plugging in an external monitor because something I read on another post while making sure I'm not posting something that's already been posted here. I tried with/without battery, with/without power plugged in. It does except SMC and PRAM resets on the times that it’s not just “spazzing out,” but it doesn’t fix anything. Google/YouTube no help. I've repeatedly looked over the board under the microscope hoping to see something obvious, nothing catches my eye. I suspect EFI chip? But I'm aware I could be way off. I don't really know where to start poking around with the multimeter on this one or if its necessary. I hope that's not too long and explains the issue clearly. I've never been a forum member anywhere I normally just read them, why? idk who cares. If there's anything I could do differently when presenting a topic that would benefit me and everyone who may share a problem, please let me know.
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