I’m surprised no-one else has said… for such a new machine, just whizz it into Apple and they have a good poke around for free…
13 months old mate! And stupidly forgot to stump up for Apple Care inside the first 12 months too… D’oh!
Anyway… For now it’s behaving itself. I’ve done an awful lot of maintenance over the last few hours, at the expense of getting jobs done in the shop.
Going to investigate getting a Mac Mini as a file server, so that I can use my own laptop or an iPad as the till in the shop if the iMac goes down again. This iMac is standalone, and though everything is backed up by time machine regularly, as it’s also the file server in essence, if it does go down then it causes a whole heap of trouble!