Installed Transend 32 gig micro sd card and Galaxy S5 reconized and mounted. I connected to pc and moved some pictures to card. I viewed pictures on and off for 5 or 6 days. A couple days later I wanted to show a friend the pictures and the sd card was not visible. I connect phone to pc with cable and no sd card. I pulled card from phone and put into pc and was reconized and viewed pictures. I turned off phone, removed battery and inserted sd card and battery again. Turned phone on and not reconized. I turned phone off again, removed battery and sd card. I put battery back in, turned phone on and inserted card while phone was on.....nothing. I turned phone off again and removed sd card. I put sd card back into pc and formatted fat32 and tried again in phone....not reconized. I bought a samsung 32 gig sd card and went through the same steps....nothing. Could this be a hardware problem or could it be some kind of a driver problem. I don't know much about phones and thought the only driver for a phone would be usb to pc connect problem. The phone when connect with cable to pc is reconized. I would appreciate any thoughts. Just frustrating.