The best way to check the hard disk is to remove the hard disk connect it to a PC (using a drive cradle), and boot the PC into linux and use the built in drive checking and repair capability of the Linux OS.
Alternatively as presumably the HDD was giving issues simply replace the Existing Seagate Pipeline with a new one up to 2TB, Other than swapping the hard drive the process is very simple. The box will auto setup a new HDD (you don’t even lose your recording schedule – as you have done a reset that’s already gone).