Hi. The hard drive on my mid-2010 unibody MacBook 13" is hiding. I bought an external drive, made it bootable with 10.12.4, and my computer works fine. (No, I hadn't backed anything up.) Trying numerous methods (e.g. disk utility, testdisk, photorec, free recovery software, all the startup commands), nothing seems to be able to find my internal hard drive. On internet recovery, "Mac OS base system" comes up, but I can't do anything with it. It's likely that I overloaded the memory by editing movies and ran out of free space. Any suggestions before I have to spend money or pull my hard disk out?!