Albeit an old thread, I'd lie to thank you very much for these instructions - I was able to update the firmware on a Samsung 840 Evo which would not work using Samsung Magician (where it was falsely stated that the most current firmware was already running).
A few notes for others who want to try this:
- On High Sierra's Disk Utility, you cannot properly partition the USB stick. I did it with the Terminal command diskutil partitionDisk diskN 2 MBR fat32 "PART1" 50% fat32 "PART2" 50% (with N being the number of the USB drive as per diskutil list) - this gives you a Master Boot Record partition table with two MS_FAT32 partitions of equal size.
- Also in High Sierra's Disk Utility, there is no 'repair' function. Use First Aid instead.
- Before you insert the Samsung Firmware ISO file into the SYSLINUX partition, you have to delete it - I used ALT-File-Delete Immediately
- I had success only with a 15" MBP 2012, but not with 2010 models
I will later see whether I have luck with a Crucial M550 SSD as well - this one is also recalcitrant to firmware updates...
Again, great thanks to the group here and particularly to
@snaky69!
Magnus