Before I sent my phone off, I created a nandroid backup on my external SD card for my Galaxy S4 and took it out. Got my phone back, popped in the SD card, booted into my recovery to restore my nandroid backup, and it says "No files found" when I tap the backup files (1970-07- I google'd around and there's some advice on creating a second backup and then using a file explorer to see where the backup is located and then moving the old backup info there and then trying to restore it, but I don't know if I can create a second backup on my external SD card without overwriting. Also, I don't think my phone has root since I created the nandroid and then unrooted with SuperSU and did a factory reset, so I don't know if a file explorer will work.

Phone is M919 S4 with Android 4.2.2 (not sure if rooted), Philz Touch Recovery. Any help/advice appreciated.