Harddisk controller doesn't recognize harddisk
A few years ago I replaced a harddisk in a friends computer. I installed a Samsung 840 250 GB. All worked well until now. Mac won't boot. Installed the HD from my macbook: Mac won't boot. I used an external bay and I can boot both HD's. I guess something is wrong with the controller. What can I do? Do I have to replace the motherboard or is there a fix?
Is this a good question?