Retrieving data from a seagate external hard drive after corruption of partition

[ramas28]

Hello, out of the blue my well-functioning Seagate 1 TB external hard drive suddenly stopped being accessible. Besides my MacBook, I tried it on another Mac notebook and a Windows system notebook. The same result. I have given it to my computers man for data retrieval. He says it is a critical situation, as the partitioning / files index system has gone. He is trying to do what he can to retrieve. Any advice? Many thanks.

 

[house70]

Has he tried to mount the HDD on a linux system?
If that fails, there are some programs out there that could be used to retrieve data from corrupted drives, with variable results.