I have a mid-2014 MacBook Pro that I bought used with no ssd or charger. I purchased a charger and nvme ssd with adapter online, but while trying to install macOS temporarily on an sd card and after a lot of googling it seems the firmware is out of date and I couldn’t get it to update past Sierra. I read that the firmware update will only work with an original ssd so I bought the cheapest used one I could find (32gb from a mid-2014 iMac) it should be the same type as the original so I thought it would work (pcie 2.0 x2).
Unfortunately, I’m still having problems. I’ve tried many different ways of installing but I’ll try to keep this brief.
Trying to update from Sierra to higher on the sd card gives me the firmware verification error no matter what ssd is installed (they were formatted so an efi partition existed)
High Sierra installer usb just boots back to the installer instead of giving me the error when installing to the Apple ssd. Also, I’ve been unable to get anything to boot off of any internal ssd, even the Apple one. And Mavericks can’t see them and Sierra can only see it sometimes. Also the high Sierra installer usb won’t even let me attempt to install to external media, it says you may not install to this volume because this computer is missing a firmware partition. But I thought it used the efi partition and there is one?
So, if anyone can help me out here I’d be very grateful. I will wipe everything and start from scratch if that’s necessary, thanks!