Failing Time Machine Backups?
I've been manually backing up wifi to an external Seagate NAS 3TB drive for about 2-3 years - successfully. About 2 weeks ago I found my TM backups going back about a month had not been successful. Attempts to backup produced hanging on "preparing backup". I then went to the web and found this solution: http://osxdaily.com/2014/03/31/time-machine-stuck-preparing-backup-mac-fix/
After doing the above I got past the hanging on "preparing backup" and was able to see the backup working, however the backup never completes and there are no error messages on TM telling me why the backup failed.
The above "fix" actually got me back as if I was doing my first backup, all previous backups were wiped out.
This started before the High Sierra update, but continues.
Can someone tell me how to proceed to solve this?
Thanks
Peter
MacBook Pro, macOS High Sierra (10.13.2)