MacBook Pro crashes before I can type in my password. What can I do?
My 15" mid-2012 Retina MacBook Pro recently crashed and couldn't boot up. I eventually managed to fix the problem by resetting the SMC and NVRAM and use it for a while. But it crashed again after about an hour of use and now the MacBook Pro crashes before I could even type my password into it. What has happened to it and what did I do?