2000XL problem after the 8 in/out installation

Hello to everybody,
i have a MPC 2000XL and i recently add the additional 8 in/outs to it.
After the 8 in/out installation, the MPC started to crush and i'm not able to do anything with it, i can't record, load from disk, save, anything.
Anybody ever had this problem?
Please reply because this thing drives me crazy.
Thanks a lot.

hmm..did you knock something loose when you were installing it?

Nope, i just add the additional 8 in/outs...

Open it and double check everything is seated properly.