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spencersmitty

macrumors newbie
Original poster
Oct 9, 2021
25
3
I’ve installed a Samsung 970 Evo Plus with the sintech adapter into my 2017 iMac 27” 5K.

was getting kernel panics (nvme fatal error) and so i decided to reinstall mojave. now that i’ve erased the nvme to reinstall, i’m pretty sure i have ruined my recovery partition and I’m having NO luck installing mojave at all using a USB installer made with terminal on a friends Mac.

image.jpg


yes, i’ve…

-updated the samsung firmware
-tried NVRAM reset, yada blah
-tried Recovery mode (goes straight to internet recovery and gives me the prohibit sign)
-erased the NVME multiple times with APFS format and GUID

pretty sure im absolutely F’d at this point.. no posts online and i don’t know what to do. please someone help me out because im about to give up and buy a new imac.
 
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You might need to recreate your USB installer. Ensure you formatted it as Mac OS Extended (Journaled) with the GUID Partition Map Scheme. I had to do this with one I recently created when it refused to reinstall on my Dad's older Mac.
 
You might need to recreate your USB installer. Ensure you formatted it as Mac OS Extended (Journaled) with the GUID Partition Map Scheme. I had to do this with one I recently created when it refused to reinstall on my Dad's older Mac.
okay, i’ll try again with a different USB drive tommorow. were you getting a similar error message?
 
okay, i’ll try again with a different USB drive tommorow. were you getting a similar error message?
Yes the very same, and also with Mojave. The drive I was doing it on was formatted was Mac OS Extended (Journaled) but it had the Master Boot Record scheme. Reformatting it to that fixed it. Good luck and hope you get your machine back up!
 
Yes the very same, and also with Mojave. The drive I was doing it on was formatted was Mac OS Extended (Journaled) but it had the Master Boot Record scheme. Reformatting it to that fixed it. Good luck and hope you get your machine back up!
thanks… haha. i’m losing faith in this whole nvme swap: don’t know how people don’t have problems like me.

cheers
 
thanks… haha. i’m losing faith in this whole nvme swap: don’t know how people don’t have problems like me.

cheers
I thought of doing that with my MBP 15 2015, but I ended up using OWC's Aura X2 Pro despite it being the more expensive upgrade at the time. It's been there for 2 years now and thankfully still stable running Mojave. Definitely miss the days when Macs could be upgraded from 2006-2012 without relying on adapters or custom drives.
 
hmm, seems setup correctly. i feel like something else is preventing it from progressing any further… but i guess it could be a bad flash drive still?

image.jpg
 
It could be a bad drive. Try a different one and see if that's still an issue. That also happened to me in another reinstall of Mojave some time back.
 
Did you download the .dmg installer directly from Apple or from another site? There was a bug in the past with these installers that had some kind of expiration date so many people were getting these errors. What about the computer that you used to create the installer? Which version of Mac OS does it have?
 
I got it from Apple's website

Previously I had to sometimes redownload the version I got from the App store too when it was previously available there.
 
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Did you download the .dmg installer directly from Apple or from another site? There was a bug in the past with these installers that had some kind of expiration date so many people were getting these errors. What about the computer that you used to create the installer? Which version of Mac OS does it have?
i downloaded it yesterday from the app-store on a 2020 iMac running Big Sur. it took like an hour to download so id hate to try it again for the same results… but no other option!

whats weird is.. before i removed my OS and i was having kernel panics, i tried downloading Mojave natively on my own appstore and i was getting a similar “could not verify update” error and the update file wouldn’t even appear in my applications folder.
 
Try rebooting from the USB flash drive.

Once it's up and running, QUIT the installer.

Open disk utility.

Go to the view menu and choose "SHOW ALL DEVICES" (this is a VERY IMPORTANT step).

Now look on the left, you should see the PHYSICAL nvme drive as "the top line".

Click on it and ERASE IT to APFS with GUID partition format.

Does it erase ok?
Now... run disk utility's "first aid" feature on it.
Do you get "a good report"?
OK, it's ready to try the OS install again, so quit disk utility.

Open the OS installer and try again.
No promises...
 
Try rebooting from the USB flash drive.

Once it's up and running, QUIT the installer.

Open disk utility.

Go to the view menu and choose "SHOW ALL DEVICES" (this is a VERY IMPORTANT step).

Now look on the left, you should see the PHYSICAL nvme drive as "the top line".

Click on it and ERASE IT to APFS with GUID partition format.

Does it erase ok?
Now... run disk utility's "first aid" feature on it.
Do you get "a good report"?
OK, it's ready to try the OS install again, so quit disk utility.

Open the OS installer and try again.
No promises...
yep.. first aid comes back clean since there’s nothing on the ssd, and i’ve been erasing the NVMe each time i’ve tried to install mojave but unfortunately no change :/

i’ve also noticed that i’ll get an occasional kernel panic when restarting the computer (just a quick refresh before i boot into the USB again).

how is that even possible? how can you have a kernel panic without an OS installed… my best guess is since the mac has no OS/nvme driver installed to support the new SSD, it throws the panic.

my mind is wanting me to believe that the kernel panic might have something to do with the installation failing.. or I might be missing some sort of BIOS file required for the nvme to write properly, that’s a streeeetch though.
 
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I'll guess that the USB flashdrive you have, has something that's "not right" on it.

I think you should go back and re-do it.

I'm going to offer an unusual suggestion, but you ought to try it.

Since you want to install Mojave, FIRST DO THIS:
Go to this page:

Download dosdude1's "mojave patcher" utility.
Here is a DIRECT DOWNLOAD LINK:

You don't need to "patch" anything, but dosdude has included an easy way to quickly download a good copy of Mojave.
Just launch the patcher.
Dismiss the "alert" if it pops up.
Go to the "tools" menu and choose "download Mac OS Mojave".
It will download to your Mac (about 5gb).

Now, you need to prepare a USB flashdrive.
It MUST be 16gb or larger. 8gb will not do.
Format it to Mac OS extended with journaling enabled, GUID partition format.

Now, you can use the Mojave Patcher utility to "build" your bootable flashdrive.
Just select the copy of Mojave you just downloaded, select your "target" (the 16gb flashdrive), and click "start operation".

When done, take that flashdrive to the problem Mac and see if it will boot and install now.
 
OP wrote:
"how is that even possible…? how can you have a kernel panic without an OS installed…"

Is the RAM in this one "as it came from the factory"?

or...
Has the RAM been upgraded at some point with 3rd-party RAM?

IF the RAM was upgraded,
Take the 3rd-party RAM OUT.
Put the factory RAM BACK IN.
Try booting again.
 
tried the mojave patcher:
unfortunately it got hung up on a stagnant apple loading bar for a half hour not moving.. i gave up.
—i think the patcher works great for grabbing the update file nonetheless, so thank you :)

i also tried another flash drive with the mojave update and got the same ‘could not verify’ error.

the only thing that somewhat made progress was to delete the InstallInfo.plist file within the installer file; that made the loading bar go for a while! but got hung up on 2 minutes remaining for like.. 2 hours… and finally kernel panicked.

i would swap out the ram, but i have already confirmed the panic is due to the nvme (something software wise i think); i’ve swapped out the ram when having kernel panics within the OS and no change.

sigh.. running out of ideas
 
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Once more I'm going to suggest:
If you still have the original Apple RAM, put it back in and TAKE OUT any 3rd party RAM.
 
I am not sure if this is your case, but I have had massive problems with a samsung PLUS nvme drive back in 2019. Kernel panics and other weird things.

I went back to the computer store and got a non plus drive. no more problems.
 
I think vivo may be onto something in reply 19 above.

Although Samsung seems to be one of the "most used" brand names in drives when upgrading Macs, it also seems I read of many more problems with them (then with other brands).

Never used them, myself.

Quite frankly, I would not have swapped the internal drive on the iMac...
 
yep! i did the firmware update.. people say it seems to fix it. and FYI, the oem blade drive in the iMac is made by samsung ?

i’m preeeeety close to buying the 2020 iMac, probably the last imac to ever be able to run boot camp since the introduction of M1. this is just so tiring to try to get this to work i’d rather buy a mac with an SSD from the get-go…
 
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