Firecuda 2TB SSHD not visible in Disc Management

Jan 31, 2019
MY PC Specs:
Dell Optiplex 3010
Intel i5-3470 Processor
8GB Ram
Old HDD - WD Blue 250GB
Windows 10 OS

The Problem:
I have a Seagate Firecuda 2TB SSHD (3.5" Internal) which is not recognised in disc management so I can not format or partition it.
Intention is to migrate all data from old HDD to SSHD and remove old drive.
Have looked at every posting I can to find answer but all blank.
Drive is visible in BIOS settings, and is enabled.
I have downloaded Seatools bootable for dos, and Disc Wizard and seatools SSD. I get the massage that there is no seagate drive installed using last two.
I have updated the BIOs to latest v.22, no effect.
I have swapped power and SATA cables over with no difference.
Have tried changing boot option from legacy to UEFI in case that is the issue, but PC will not boot, so back to legacy.
The drive is actually a replacement unit just received under warranty as original unit encountered same problems and it was swapped, so unlikely to be the drive itself.
Any suggestions ???
Jan 31, 2019

When I first bought the Firecuda I installed it in my previous PC (Dell Inspiron 620, Windows 7 OS) but I experienced exactly the same circumstances. That PC has been replaced and hence trying to install drive to replacement PC now, when problems repeated. After lot's of tests the Firecuda became suspect - and was returned under warranty and has just been replaced with a re-certified unit. But issue still exists, despite different PC and different Firecuda drive.

I have contacted Seagate support APAC. They would not give me direct assistance over the phone, insisting I send screenshots for them to investigate. After I sent the screenshots, they have sent a short email suggesting it is a problem with the BIOS settings, or Motherboard. They have not explained why none of their software products (incl bootable dos version), will work either. Prior to contacting them I had paid for paragon migrate software, and have also downloaded macrium reflect, neither of which can recognise the drive either.

Taking the Seagate support comments, I have updated BIOS to latest Dell version 22, but that has made no difference.

Dell can't / won't tell me if motherboard is compatible with the firecuda as it is not a Dell SSD, but if it isn't compatible then the same problem has existed in 2 PC's with completely different motherboards and surely would be much more widely known about in Seagate ?

Unfortunately I don't have another Desktop PC to try this into now, so as a last resort I have ordered a USB 3.0 to SATA adaptor cable, suitable for 3.5" drives (with power supply) and as soon as that arrives I will test through a USB port. But this is getting pretty desperate right ?

I have literally spent hundreds of hours chasing this problem around. After so much time and $ invested I'm determined not to be beaten (I'm rather stubborn / stupid !!)

Any advice greatly appreciated. Thank you !