cgsecurity.org

Some data about the 3 TB Seagate Harddisk:

ST3000VX000-9YW166 Information
Common characteristics
Manufacturer Seagate
Model ST3000VX000-9YW166
Capacity 2.7 TB
Interface SATA
SATA version 3.0
Firmware CV13
Alternative firmwares 1
Firmware upgrade supported
ATA version 8 (ACS)
Advanced Format supported
Units tested 15
Times tested 49
Performance
Maximum interface speed 600 MB/s
Maximum buffered read speed 448 MB/s
Maximum read speed 207 MB/s
Minimum average access time 6.65 msec
Volatile write cache supported
Read look-ahead supported
Command Queuing Optimization (NCQ) supported
Advanced Power Management (APM) supported
Acoustic Management (AAM) not supported
Rotation rate 7200 rpm
Reliability
Count of sensors 20
Free-fall Control not supported
SCT Transport supported
Duration of full self test > 255 minutes
Maximum temperature limit 60°C (140°F)
Maximum recommended temperature 61°C (141°F)
Highest temperature 69°C (156°F)
Average highest temperature 47°C (116°F)
Security
Drive access restriction supported
Enhanced security erase supported
Complete destruction of information 330 minutes
Instant information destruction not supported
Hidden partition supported
Partition access restriction supported
Trusted Computing not supported

Thanks a lot for looking into this.

You need to rerun Testdisk in GPT mode as your drive is beyond 2 TB size, the sector size is 512 byte and there is no converting electronics enabling the administration of more than 2 TB of space.

OK. Thanks a lot for the advise, recuperation, I will do it & post results here.