a change in the menu bar icon perhaps?
Is the drive you back up to, still functional?
Is it always connected and powered on/
P
My wife and I both are using (or thought we were) Time machine. I had my HD crash and when I went to get my backups they were not there. My wife checked her TM and it stopped backing up 3 weeks ago even though she has changed many files. What is the problem?

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