The ssd boots perfectly when connected over usb but is not found when connected internally. When you use startup disk preferences to set mac boot from an external drive so it ll boot from that disk until you choose a different one.
However when i updated de ssd s firmware i booted from a cd with the ssd connected internally and it was found without a problem.
Macbook pro boot from usb but not internally. The machine will start to boot from the usb drive. If your usb thumb drive usb external disk or flash storage contains a usable operating system or a macos installer you can select it at boot time using macos built in feature called startup manager which can be invoked via a simple keystroke. At this point you can also use the mac installation disk to boot your mac from.
I get to the home screen and the hdd is recognized and i am able to save files to it. You need an uefi bootable image. If you press and hold down the control key while making your selection it will be saved and your computer will boot from the usb every time as long as it is left in the computer.
I have a mac book pro 13 mid 2009 model. Plug in your bootable usb device and boot up your 2018 2019 macbook pro from usb hold the command key and you ll see the startup disk screen select the usb and boot it up. When i boot with the ssd internally connected i just end up with a grey screen and a fold questionmark icon.
I was able to make a bootable usb with the os x on it and it boots normally i follow the same steps with the ssd and it boots via usb 3 0 adapter. We re uncertain of other workarounds for grub at this time. 1 turn on or restart your mac.
The problem that i am facing is that when i switched the internal drive to upgrade the hard drive both hard drives stopped being recognized although i can boot up from an external usb the internal drives wont boot up from startup. When your macbook pro refuses to boot from internal hard drive you can set it to allow external boot by selecting allow booting from external media in startup security utility. External boot feature is the one that controls whether your mac can boot from an external hard drive thumb drive usb drive cd dvd or other external media.
As a last effort i booted from the ssd via usb adapter and stuck a 2 5 hdd internally. Caveats notes and disclaimers. Go to apple menu system preference then click startup disk.
Set a mac boot from usb drive using startup disk.