Run Rufus but without selecting any image, just press start. It worked for me numerous times.
sent from my G2
SD format didn't work Rufus also failed to work. also did the diskpart & sadly it wont. i got 2 micro sd cards both brand new from Sandisk. both are "dead"
Same issue here for me. Tried with rufus & also the image provided here but the sd is still on 31MB