In a quiet room while holding the My Cloud NAS against an ear, you can power-up the NAS. What you can be listening to is for, maybe, the drive spinning up and spinning down and alternating with this. Another tell-tale sign is if you can hear a pattern. By this it will be the drive trying to find a track on a disk platter. It’ll be a repetitive sound. The sound of a hard drive struggling is a bit difficult to miss.
If the sounds from the drive are pseudo-random then it’s a better sign.
Whenever I encounter a hard drive that’s got problems that’s what I try to do first. Listen to it. (Bit like a doctor listening to a patient’s chest.)
@Great_Scottt, is also correct with it being a NAS, when powered up it will be trying to possibly write to the drive on power-up. This and also if there is a physical fault would make it more difficult for data to be recoverable each time an attempt is made to power-up the drive.
I’m guessing the My Cloud was powered when it hit the ground? Not good.
I once managed to drop a drive. Cried for a while. With the NAS I have now, it’s in the other room, in a corner where I don’t have an reason to go there often and also located where the frequently visiting dog can’t get to it to knock it over. Lesson learnt once suffered the pain.