Micro SD card hardware?
My lg g3 (Lolipop) keeps "unmounting" my microSD card. I've tried several cards and the same thing happens. Could it be hardware and should I (could I) replace the microsd slot?
A large smartphone by LG, released in fall 2014. The LG G3 (D855) boasts a Quad HD IPS display and a 13-megapixel camera.
You may want to first check the slot for lint or some other material that may be killing the connection. Otherwise, you may want to try backing up your phone, reformatting, then restoring your backup. I've seen some people on other sites having success with that. Might be a risky solution but worth a shot before having to open it up and replace the slot.