Two weeks ago, a friend's mid-2012 MacBook Pro gave the dreaded question mark folder upon attempting to wake from sleep. I pulled the drive and checked it (backed up, SMART status passed, 70+ MBps read/write - pretty good for an old 2.5" spinner). I booted to AHT and ran full hardware diagnostics. It came back with no errors. I know that HDD cables in these machines fail regularly, so I replaced the cable with a used one I bought from PowerbookMedic.com. It worked!
About a week later, the exact same thing happened - a flashing question mark on waking from sleep. So my question is:
Could a different piece of hardware be failing/did I overlook something? If so, what? If not, what are the chances that this new cable failed so soon after install? More importantly, if I exchange it for another used cable, what are the odds it will fail quickly again?
Important notes:
- HDD is known good
- Once the flashing question mark folder shows up the first time, nothing will boot attached to that cable (attempted with Win10 SSD, macOS HDD, multiple attempts made - the first time this occurred, a cable replacement solved that issue).
- Computer will still boot and operate effectively from HDD when attached via USB
Please don't hesitate to ask any clarifying questions!