Reinstall the OS as from the factory and see if that cures it. If not, have it repaired.
I have a medion Win Xp Pc
and it had a 5 in one memory hardware block.
But when i insert a sd card the led on the outside lights up but i can't acces it. No pop up, nothing
i checked hardware page and i find it in the lsit sais: It is working ok and it is activated...
What could cause this?