Just bought a refurb, what should I be looking for?

[parkemon]

I took delivery of a 27", 3.5 i7, 16GB RAM and 780M (was supposed to get 775M, but I got lucky) refurbished late 2013 iMac. Everything seems to be in order, but I'm not sure if there's some diagnostics I should run, or glaring issues I should be on the look out for. I don't notice any yellowing of the screen or image retention as of yet.

I've got another week until the return policy is up, so I'd appreciate any input. I realize that if I'm happy with how it's working and looking, looking for issues shouldn't be a priority, but I just want to make sure.

Appreciate the help.

 

[Altemose]

You can run Apple Diagnostics on there. That being said, just enjoy the Mac. Worst case scenario, it is covered under AppleCare for a year with the option to extend. Refurbished Macs carry the same warranty as a brand new one.