[Elecraft] K2 Dead above 40M

[K8RS]

Guys,
          Help!

         Loaned my recently completed K2 to a good friend who was interested
in building one.  He called to say that the radio died on him above 40M.  He
said, "I may have punched the wrong button  or something...."  When I picked
it up from him it was not receiving or transmitting above 40M.  Seems to be
fine on 40M, 80M and 160M.  What could he have done?  The K2 seemed to be
working fine prior to the loan. I am going thru the manual to see if there
is something obvious I have missed.
           Roger K8RS