A few years ago I reported a problem with a Humax Freesat receiver which I successfully repaired. Well, until yesterday, the box has behaved itself perfectly.
I also noticed something strange when I started to disconnect the box, the space below the TV has gained a load more cables and connections since I last had to look at it! It really was a mess.
Anyhow, all untangled now and the Humax fault was indeed another capacitor failure (not the same one though) so the details in the original post will help if you get the same problem.
All is now fixed, and for the princely sum of 54p (for the 680µF 25v high temperature capacitor from Maplin) and about an hour of my time – most of that spent untangling!