New
#11
Look on the Downloads page for your model's for Data Lifeguard ISO.
If there isn't one then you can try it from Hiren’s BootCD 15.1
or Ultimate Boot CD (UBCD) from a USB flash drive | USB Pen Drive Linux.
If you can't run maker's HD Diagnostics then you'll need to rely on Dell Diagnostics via F12 at boot, which I see you already ran.