Trouble booting from USB?
I have two MBP's that I am have difficulty installing OS X on. I replaced the HDD's and went to install OS sierra on both machines. I got them to boot from the flash drives (start-option) and they both are just stuck at the apple load screen, both in the exact same location as well, with no progress. I tried resetting SCM, PRAM, I've swapped out the RAM, even tried different HDD's. I am at a loss. I know the bootable flash drives work because I just installed OS X on a few iMacs. My next step is to just clone the drives from a working computer, but I want to know what is going on. I have also tried El Cap bottle flash drives with no luck. Thanks.
Is this a good question?