Thxs for the reply,

The unit fans are working (starting mode 2 times fasten up and than a normal constant speed)
a green lamp next to the fans (on the front of the case) lights up,
a green led on the inside of the board is also lighting up.

thats about it..
my router displays thats there is nothing connected.
could it be that the TPLINK unit is broken down?
or did i missed something.