SD Card Wont Stay Mounted

[acableman]

I have an LG G3. I have been wrestling with this problem. I upgraded to lollipop and it did not help. My phone sees my card. I erase/format and it mounts. I copy files photos and music to the card. Everything works fine. Then after a while just at random the card unmounts. When I click "Mount" it does nothing. Restart the phone, nothing. Take the card out and put it in the PC. It won't read the card unless I format. I format the card and I'm back where I started. The card mounts and I'm able to copy files to it.
Is this just something that can't be done. I'm ready to just give up. I've tried two different cards. Both are class 10 128gb.

 

[leeshor]

Welcome to the forum

Have you been using the phone to format the cards? If so check the cards in a PC using a card reader to see how it was formatted and try do9ing it a different way. Either from NTFS to exFAT or the other way around. Also what brand and have you tried any smaller cards?

 

[acableman]

Welcome to the forum

Have you been using the phone to format the cards? If so check the cards in a PC using a card reader to see how it was formatted and try do9ing it a different way. Either from NTFS to exFAT or the other way around. Also what brand and have you tried any smaller cards?

I have formatted in the phone and PC. When I format in the phone and then put in PC it won't recognize the format and says I need to format. I have done the Full format in exFAT. Haven't tried NTFS

 

[leeshor]

I'm going to take a wild guess that the problem is the fact that it's 128GB. You didn't mention if you had tried a smaller one. The specs say that size is supported but that may still be a problem with some brands/cards.