Fairlight-CMI

A plea for some help from somebody in the group.  I have been trying 
to sort my Master Card to solve a problem with my IIx.  The computer 
part works well but the sound bit doesn't and I suspect the Master 
Card.  When I run the CMI diagnostics disk for the Channel cards it 
throws up errors about memory being all one value.

What I am after is either a Master card to borrow/buy to test the 
system or somebody who could try my Master Card to see if it is the 
cause of the problem.

I live near London so if anybody can help I will be very grateful.

Thanks,
Tony