Dell Poweredge 2950 refusing to boot from HDD

First post here, so be gentle.

Recently, our trusty 2950 decided to throw errors after a new HDD was added to the RAID Controller. Now, on this server we have Server 2016 Installed. We added the new HDD to the RAID Controller and configured everything as it should be. We added two other drives to this server following the same steps as before with no issues.

After we added this drive, the server kept throwing a 0x00000c error, saying that a boot device could not be accessed on boot. We then tried to repair the drive using a Windows Install USB with Server 2016 installed, and tried to boot from the USB in order to access the tools. The server refused to boot from the USB, even though USB boot was enabled in the BIOS and the USB was selected as the boot device by pressing F11.

We then decided to install a fresh copy of Windows Server 2016 in Evaluation Mode on an older SATA HDD. We used another PC to install the OS onto the HDD. We added the HDD to the RAID Controller using the RAID Controller's BIOS, and tried to boot from that. Nothing happened.

When the server reaches the end of its POST cycle, a blinking cursor appears at the end of the report, after it asks whether we would like to access Network Access Setup. This happens no matter which HDDs we load onto the RAID Controller. We even deleted our old RAID configurations just to get the system to boot from something.

We tried clearing the NVRAM using the jumpers on the board, but that didn't help at all.

The server is using a PERC 5/i RAID Controller, and is currently on DELL BIOS 1.3.7.

Any help here would be greatly appreciated!