[Q] Lt15i only charging no access to sdcard by pc topic

Hello guys i just got new pc case so i installed the hardware and i put my usb cable to usb 3.0 front and my phone it started normally so i copied some photos and i safely remove it.. Then after some minutes i used again the usb but the phone was only charging i couldnt find my sdcard-phone on device manager. So i changed usb port back panel (2.0) and it worked properly :/ any solution? i cant pull always my heavy pc so i can use my phone on the pc! Excuse me for my bad english!