davidskeck I can enter the Fastboot Mode screen, but when I attempt to either enter Rescue Mode or Recovery Mode, the boot loop begins again at 1.
So to confirm, when you press the power button to enter recovery mode, you don't see after 10 seconds an Android lying on its back with "no command" written below? If you manage to get to that screen then you've entered recovery mode correctly.
This could indeed be indicative of a hardware failure, and if you're not able to get into recovery mode, then you may indeed want to return the device.