Have you looked over the IFIXIT guides for this model?
[[Topic:Acer Nitro 5 AN515-53-55G9]]
The battery replacement guide shows the parts best.
This may also help to show you how to remove the drive properly:
https://us.answers.acer.com/app/answers/detail/a_id/49882/~/hard-drive-installation-instructions-for-acer-aspire-nitro-5
Your hard drive looks like it is sitting on the cover so I’m guessing you did not take off the hard drive cover off, gently removed the hard drive and disconnected its cable, '''before''' removing the main cover? Maybe not?
I see the hard drive connector, in your not very clear photo, connected to the drive sitting on the main cover so it looks like you inadvertantly yanked the other end of the drive cable away from the connector ON the motherboard.
The ribbon cable connects near the cooling fans. If the fan is covering it
So flip the cover over and correctly remove the hard drive cover and drive module. Disconnect the cable from the drive and reconnect the ribbon cable to the slot for it on the motherboard.
Need more help with this please ask before doing anything.
Good luck.