I bricked my YN685N flash yesterday by updating to the latest 1.3.8 firmware. I was using windows 10 on my comp. Then after fiddling a lot with other combinations tried older firmwares. Couldn't find any anywhere. Then while searching online, I found a reply which advised to update firmware from a windows 7 pc. Did that today and now firmware updated successfully. Thanks to that contributor.(Couldn't find that thread anywhere today) Posting this here so it can help someone else.