Challenging problem-hard drive malfunction

We need as much information as you can possibly give us. If you saw "device not working," how would you go about giving advice?

Need more details.

Have you tried a different power cable and a different data cable. Or at the least unplugginf and plugging them back in.

Is it a new build, old build. If old sometimes cables work loose over time

How old is the HDD? If 3+ it just might have taken that big data dump in the sky.