Mesa 7i96s Inputs won't work

Hi,
we installed LinuxCNC with a Mesa 7i96s. The Servomotors and  the outputs are working fine but none of our imputs are working.
we wired inCom to GND and In00 to +5V but neither the onboard LED or the Halshow shows anything.
Is there anything to try or to do? Is the board dead?

thanks
- Tobias

Are you sure you have input common (P3 pin 12) connected correctly?
An LED/Input might not work if it had been mechanically damaged, thats
the only other thing I can think of.

We measured the voltage between common and in00, it was close to 5V.
Is there any Option to confirm a mechanical damage?

Try another input

Sadly I tried every input

Sounds like your input common connection is not connected