I downloaded that program and the Bitmain.img file in the quotes but My win32 disk Imager program doesn't offer any option to format. I can format in windows explorer under fat32 I used "Default Unit Size" as Allocation unit size optionquick format checked. I tried to do this to one miner and it worked! Only after i bought a new micro sd card, I think re-writing the micro sd a bunch of times corrupted it. I'll try the same on the other two now.
OK Update.. Good news all 3 1TH/s miners are hashing, the problem was with the Micro SD cards. 3 new Verbatim 8gb cards & it works.
If you SSH into the OS and do a shutdown prior to powering down, you will greatly reduce the chances of trashing your SD card. The problem is likely to happen when you power off while a program is writing data to the file system. MBP Bitfury rigs delivered last year also had the same problem. Of course, getting good SD cards like you did also helps a lot.
Has anybody figured out why this is happening? I can't find anything in the OS that writes to the file system.
I'm way out of my league here BUT
IF you have more than one S2 I found I could copy the good file from one SD card and then
after deleting all the files on the other card just paste them in.
Of course you need to only have one running at a time since both would have the same IP address
and would need it to be changed to another...so you don't have conflicts...that can cause problems too
needing to do a reset to default.
You could also just have someone mail you the SD cards contents IF you only have 1-S2...