iPhone 5s Error 9: Can't restore through DFU or Recovery

Hey guys, I recently got a used iPhone 5s from eBay, and the seller says that it's working, it's just that it's not restoring because of her computer firewall (Error 3014).

I've got it today and tried to restore it through Recovery and DFU mode, but quickly ran into Error 9, a flashing blue screen and then back to recovery mode.

I've opened up the 5s and checked for the long screw damage, but the bracket and the screws were not there anymore, same goes for the battery bracket. A close inspection says that the bottom right screw hole was not damaged (it's completely black down and doesn't seem to be damaged).

Other things that I've tried but to no avail:

- Restoring while screen, TouchID, digitizer and front camera flex are disconnected (DFU and Recovery)

- Forcing iPhone to get out of recovery (but instead got a red screen + boot loop)

At this point I am very sure that there's a problem with the hardware itself, but have anyone ever had this problem before? And what should I look out to resolve this?