I've worked in IT and tech for over 30 years.  I've deployed, imaged, and repaired thousands of PC and Mac laptops and desktops.  How a company could let this computer out the door as "refurbished" and fully functional is a joke.  From the first start up something was majorly wrong and it does not take a rocket scientist to understand this computer was nowhere near ready to be deployed.  After hours of troubleshooting I was able to determine the fusion drive was corrupt and probably had some form of internal physical damage.  Literally whoever approved this iMac to be released has no idea what they are doing.On top of that the return process only allows for UPS pick up and not a drop off.  I live in a massive building so getting in contact directly with a UPS driver is a major hassle.  Complete waste of my time.