Chosen Solution
Hi, I’ve had an almost identical problem, a tech looked at my iMac for a whole week and was unable to identify the source. I could not even start off an emergency disk/usb reliably. He cleaned the iMac out and it seemed fine for another week or two, until today when i attempted a restart and got the grey apple screen and spinning wheel stuck (i notice the HD makes no clicking sounds when this happens How did you come to the conclusion it was the HD cable?
It could either be the MAC sata cable that connects to the drive or it could be the drive itself. I would take the drive out of the machine and hook it up externally to a machine or if you have some sort of external enclosure. I would check to first see if the drive is readable and that the files are intact. If the files are visible, I would then run a check disk.
