If that means you took the cover off the hdd then hdd is now scrap.....toss it.
I have this 1TB HDD that I bought from Ali Express. Has been working fine now for 2 years. But y'day it just stopped working after adding a few videos to it. So I tried to format it (since I didn't care much about the info stored on it). As soon as I plug it in it opens a File Explorer window along with a smaller Windows window that says 'You need to format the disk in Drive G before you can use it'. But when I click on 'Format Disk', it won't format & gives an error saying it cannot be formatted. The file explorer window open & stays open forever. After doing some reading on this site, I opened up the HDD & watched what happened when I click on format. It makes a whirring noise & the needle goes back to home. I shot a video of it as well. My computer is Win 10 Home edition. Anyone can help with some suggestions?