I have a usb hub (which I can power from a charger) and I can read a usb stick or sd card (in a reader) if connected to my laptop. I have tried connecting this via mini usb connector to this tablet (P76TI Teclast) but I can't get the file manager to see it - I want to be able to view e.g. files & photos on these devices plus copy from the sd card onto the usb stick (as a backup while I'm on holiday). This worked ok with a previous "midi" I had. Any ideas please?