Chosen Solution
Normally the question mark is a failed hard drive. I’ve replaced it with a brand new drive.I was able to install OS and reboot normally a few times. But now it boots to a lit screen with nothing on it, and after about 20 secs I get question mark. As it’s not the hard drive or RAM (changed that too) any ideas? I have reset PRAM and SMC also, but not worked. also tried booting with battery disconnected, but also not worked.
It may be a faulty hard drive cable. Its a pretty easy replacement, if you have done a hard drive you shouldn’t have any difficulties with it. If you live in NZ you can get one from us here: https://smashedit.co.nz/product/macbook-… Otherwise you could get a new one from ifixit here: MacBook Pro 13" Unibody (Mid 2012) Hard Drive Cable
