Sadly it seems like when your PSU died, it took your HDD with it 😔
I suggest that you double check on another PC before considering your next options, which are, warranty (do not tell them about the PSU), data recovery if you don't have a backup, find a PCB for the same model AND firmware revision to try your own data recovery / HDD revival as the PCB is usually the part that gets fried, or put it on some concrete you don't want, put on some safety glasses and hit it with a hammer a few times and bin it.
Fingers crossed 🤞