If it's an External hard drive, check to see if there is a reset button. The actual hard drive may be OK, but the power supply might be fried. You could remove the bare hard drive and connect it directly to the computer or put in another enclosure.

First of all, if you take it out of the enclosure, be very careful as some of these are designed in such a way that they break easily.
If it's toast, you can send it out to be scraped, or you can roll the dice with a PCB swap. You need to carefully remove the PCB with a torx driver, then send it out to be swapped (you can't swap it yourself, the firmware needs to be transferred). The PCB swap runs $50-$60; if it doesn't work, then you are looking at a scrape which is expensive. It could involve replacing the head assembly, etc., in a cleanroom. Hopefully it's just a fuse in the external box, but, sadly, it's more than likely the PCB. Odds are with a power surge it can be fixed with a PCB swap, but you never know. I really don't recommend opening the drive itself, ever. When hard drives fail; it's a bummer.

These are handy when using bare drives, if you don't need an external enclosure, just plug in...

https://www.amazon.com/Thermaltake-Sata-HDD-Docking-Station/dp/B0012Z3MKW

https://www.amazon.com/Thermaltake-Sata-HDD-Docking-Station/dp/B0012Z3MKWhttps://www.amazon.com/Thermaltake-Sata-HDD-Docking-Station/dp/B0012Z3MKW

oops. double post on the dock, here's a SATA HD bay

https://www.amazon.com/StarTech-com-5-25in-Trayless-Mobile-3-5in/dp/B000KS8S9W