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Cant load OS from SSD, bootable usb, etc. Getting white crossed circle. Got this after trying to do testing…
You’ll need to re-install your MacOS via internet recovery, restart your system and press and hold Command (⌘) and R keys. Reference: Mac startup key combinations But you have a bad HD SATA cable! follow this guide MacBook Pro 13" Unibody Mid 2012 Hard Drive Cable Replacement and here’s the needed part MacBook Pro 13" Unibody (Mid 2012) Hard Drive Cable. There are a few issues with this series as the uppercase internals are rough and over time wear the cable. Follow this Your Hard Drive Cable Is A Ticking Time Bomb In addition, incorrect folding of cable can also damage it! Use a Bic pen ink straw or bamboo cooking skewer to help you shape the radius curve at the folds. You want nice arcs not a sharp bend as that will damage the cable.
