I bought a 64GB card for $29.95 form Ebay last week , the Card mounted and reported correct capacity. My videos would copy to SD card with no problem, but when I tried to play some videos I would get the error message that this video can not be played. I researched a lot on the net to find a solution, mostly what I found was related to video format and codec. what was sinister about it was the same video that played before if it was reloaded again would not play. After a lot of tries to find a pattern, I noticed that anything written to card after 4GB capacity was passed did
not exist on the card. I found a software called H2testW that test SD cards, the software confirmed my suspicion that was indeed a 4GB card see the report posted here. I contacted the Ebay merchant to return the card , he immediately refunded my money and did not even ask me to send the card back. I bought a real 64GB card locally then all my problems went away. I guess these scammers have found a way to change the FAT on a cheap and slow 4GB card to report itself as 64GB card, and not report error when the card is full this allowed the card to be written to in phantom memory addresses . The H2testw is slow I just ran it pass 4GB. Buy your SD card from reputable dealer, otherwise the chances are you will get fake card.
Warning: Only 4377 of 63960 MByte tested.
The media is likely to be defective.
3.5 GByte OK (7537991 sectors)
696.3 MByte DATA LOST (1426105 sectors)
Details:0 KByte overwritten (0 sectors)
0 KByte slightly changed (< 8 bit/sector, 0 sectors)
696.3 MByte corrupted (1426105 sectors)
0 KByte aliased memory (0 sectors)
First error at offset: 0x00000000e60a8e00
Expected: 0x00000000e60a8e00
Found: 0x0000000000000000
H2testw version 1.3
Reading speed: 14.3 MByte/s
H2testw v1.4