Sorry this is rather lengthy but trying to give as much info as possible
MBP, mid 2010, OS 10.6.8, 2.4 GHz Intel Core i5. 4GB memory.
Verbatim Portable USB 3.0 Drive. 1TB, two 500GB partitions. Powered from USB port. Disk Utility shows drive as 1TB WDC WD10.
Both partitions show as normal on desktop. Partition 2, used for general storage, connects and works as expected. Partition 1 is used as Time Capsule but has lost its connection to Time Machine. TC shows one folder - Backups.backupdb/(username)’s MacBook Pro/ and contains one “in progress” file (the one that started and stopped very quickly yesterday). Otherwise, folder appears empty. However, the contents are still there since it shows only 16.24 GB available out of 500. Disk Utility shows it contains 274,878 folders.
Trying to start backup leads to this message:
Much searching on the web has come up with possible solutions for a reunion, a few of which I've tried, but some involve starting the MBP with the Verbatim attached. Trying to do that results in no startup, just a series of start-up “bongs” until external drive is unplugged. Then MBP starts correctly and accepts disk when it is plugged in again.
I’ve repaired permissions, repaired whole disk drive (showed as all OK). In fact done anything in DU that might help.
Any further suggestions most gratefully received.
Late edit: Opened up Trash on MBP while drive was connected and found Backups.backup.db folder with all the Time Machine backups in there. Taking one at random shows it’s the full file, not an alias
“/Volumes/Time Capsule/.Trashes/501/Backups.backupdb/***’s MacBook Pro”. Info is still calculating size. Disconnected drive to stop anyone (especially me

)accidentally emptying Trash, at which point, as expected, they vanished from Trash.