Do you have a 27″ iMac with a 3TB internal hard drive? If so it may qualify to have the hard drive replaced under a replacement program that Apple just started. The iMac would’ve been sold between December 2012 and September 2013. If you think yours may be affected you can follow the link below and type it in the serial number. If it does qualify please get in touch with us at 507-529-9600 and we can help get that replaced for you.
You can see check out if your serial number qualifies at Apple