Why is my Time Machine backup failing to fire at the hourly interval?
I know you've said there are no messages in Console.app, but you haven't specified how you've searched.  So firstly follow the steps below, and just add a comment to say whether you find anything.


Open Console.app
Select 'All Messages' in the left hand pane
type 'backupd' in the search box in the top right


Are there any messages in here related to the backup doing anything at all?