Probably would've helped to explain a bit more in detail
To get this to work, you have to make the USB drive "bootable". The drive that Samsung sent me was formatted in FAT16, with the bootable flag. The files were then just dumped to the root of the drive. That should work, but you may have to use a 3rd party app to make the USB drive "bootable" and then just dump the files on it.
At that point, we just inserted the USB drive, powered on the panel, and hit F12 to access the boot menu. It has been a couple months since we restored the panel so I don't remember exactly what option I hit to get it to boot.
I'd upload an actual .iso, but for some reason I can't seem to get it to create one
The only image that I have available is an Acronis .tib image file. If you have Acronis, then I could put that up on the server for you to download and try.