Time Machine stopped doing backups

Question

All of a sudden, Time Machine won't do any more backups. I'm not getting any error messages or anything like that - it's just not backing up automatically. My last backup was OVER an hour ago. I can do a 'Back Up Now' manually, and it will work. But the *automatic* backups simply will not happen. Why is it doing this, and how can I fix it?
Yes, I've read that Pondini thing, but nowhere in it does it mention what to do if TM just decides not to automatically back up anymore.

Answer 1

If you have more than one user account, you must be logged in as an administrator to carry out these instructions.
Launch the Terminal application in any of the following ways:
☞ Enter the first few letters of its name into a Spotlight search. Select it in the results (it should be at the top.)
☞ In the Finder, select Go ▹ Utilities from the menu bar, or press the key combination shift-command-U. The application is in the folder that opens.
☞ Open LaunchPad. Click Utilities, then Terminal in the icon grid.
Triple-click the line below to select it, then drag or copy into the Terminal window — do not type — and press return:
sudo launchctl list | grep backupd
You'll be prompted for your login password, which won't be displayed when you type it. You may get a one-time warning not to screw up. You don't need to post the warning. If you don’t have a login password, you’ll need to set one before you can run the command.
Post any lines of output that appear below what you entered — the text, please, not a screenshot.