The Mac was overheating and shutting off. Had to use ice packs to get it to boot. Thus diagnosed the fans had stopped working . . .
The only hitch was when the new parts came I spent a few days dithering whether to operate myself or take it to someone more qualified.
With the help of Ifixit's great manual, I decided to tackle it myself.
Went really well. Took about an hour to replace both fans. Now Mac seems cool, calm and collected again.
Pay close attention when you disconnect something. Keyboard cable popped right off, but I spent 10 minutes trying to puzzle out from where when reassembling.
Thought I had a system for the screws, yeah right. Finally sorted them by size and type, read the manual for their location and case reassembly was then a breeze.
Have a tool for picking up and placing connectors. I was trying to use my fingers and they're just to big to be wandering around in Lilliputville.