How big is your card ? T68 supports only up to 32Gb.
Do you know how to look at the logs (dmesg)? Does it show anything that might clear up why it's not working ?
I wanted to try mine. I remember that at some point it worked (see below though). However as soon as I've touched it I remembered why I had to let it go and move onto the Boyue T62: click here and something else opens, put the card in, the thing reboots. After it comes back on I try to connect it to the PC and then it starts flashing the "mount storage" dialog, etc.
A nightmare. And to think that sometimes I think of turning back to it bc of the beautiful screen :|
I said "see below" bc even though at some point I could mount the card in my Linux (via the T68 of course), I could never really use the card in the T68 bc it has it's share of issue card related
However, I really hope I have a buggy one and yours is working correctly, I don't want to spoil your joy.