Chosen Solution
My unit will give a “? in a folder” symbol at startup. Removed and connected hard drive externally and unit boots up and operates fine. Ordered and installed a new cable that connects hard drive to logic board. Same problem; “? in a folder symbol”. Ran hardware test on startup and it is OK. Need some help please.
Your systems PRAM setting is messed up! So your system doesn’t know which port your boot drive is located. With your drive properly in place restart your system and Press the Option (⌥) to gain access to the Startup Manager, select your internal drive and you should now be booting up under it. We still need to get this firmly set still. Go to your System Preferences > Startup Disk, unlock the setting select your drive and then hit the Restart button. That should fix things. Reference: Mac startup key combinations If it doesn’t then the replacement cable is bad or damaged. Did you reformat the drive and install a fresh OS onto it? Many a time the data on your drive is not clean because of the bad cable. I would first make a full backup using TimeMachine then redo the drive and restore your stuff back.
