Terasic DE2-35 - No Clock

Hi,

since a few days i can't use my designs.It is not possible to activate the clocksignals.I had tryed Pin N2 (50Mhz), Pin D13 (27 Mhz) and also ext. Clock (SMA conntector).My Testdesign was a blinking LED.The Flashtime was 1 Sekunde.But nothing happend.Is my board messed up? This board is 6 Years old.The last project was a x86 system with Dos and Windows (Zet).

Guido