So, I had a bit of success with getting the Nano booted. I placed the SD card I used to burn the JetPack image to back into the Ubuntu PC I am using and there were some errors reported. Note, I used Etcher to burn the image on to a 32Gb uSD card.
This is what was seen in dmesg.
[ 3480.214799] usb-storage 2-4.4:1.0: USB Mass Storage device detected
[ 3480.214986] scsi host7: usb-storage 2-4.4:1.0
[ 3481.245848] scsi 7:0:0:0: Direct-Access Mass Storage Device 1.00 PQ: 0 ANSI: 0 CCS
[ 3481.246297] sd 7:0:0:0: Attached scsi generic sg4 type 0
[ 3481.496082] sd 7:0:0:0: [sdd] 62521344 512-byte logical blocks: (32.0 GB/29.8 GiB)
[ 3481.496698] sd 7:0:0:0: [sdd] Write Protect is off
[ 3481.496702] sd 7:0:0:0: [sdd] Mode Sense: 03 00 00 00
[ 3481.497336] sd 7:0:0:0: [sdd] No Caching mode page found
[ 3481.497342] sd 7:0:0:0: [sdd] Assuming drive cache: write through
[ 3481.506470] GPT:Primary header thinks Alt. header is not at the end of the disk.
[ 3481.506473] GPT:25165823 != 62521343
[ 3481.506474] GPT:Alternate GPT header not at the end of the disk.
[ 3481.506476] GPT:25165823 != 62521343
[ 3481.506476] GPT: Use GNU Parted to correct GPT errors.
[ 3481.506500] sdd: sdd1 sdd2 sdd3 sdd4 sdd5 sdd6 sdd7 sdd8 sdd9 sdd10 sdd11 sdd12
So, I tried burning the image again but that resulted in the same issue.
Looking at the device with fdisk, I seen this issue.
sudo fdisk /dev/sdd
Welcome to fdisk (util-linux 2.27.1).
Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.
GPT PMBR size mismatch (25165823 != 62521343) will be corrected by w(rite).
GPT PMBR size mismatch (25165823 != 62521343) will be corrected by w(rite).
Command (m for help): q
I then opened gparted and it reported there was unused space on the uSD card and if I wanted to let it allocate it; I said yes. So, there is now an unallocated partition.
I then placed this back into the Jetson Nano and it booted without issue.
I had read somewhere that if the uSD card was larger than 16Gb, the Nano will automatically resize the image to fit the uSD card. Is it possible that this process was taking place in the background? Previously I did leave the Nano running at the Splash Screen for at least an hour or so and it did not show any change. Should I have waited longer?
Sorry for the extended post.