[TenTec] Deaf Orion

[William Terry]

In the contest today my orion suddenly lost about 50% of its sensitivity.  It was like the attenuator was engaged.  The band became very quiet except for the very strong stations.  It affected both rcvrs.  I tried reset,  reloaded an old firmware, changed antennas all to no avail.  It was just like a sudden solar flare. Other radios with the same antenna were working fine so it has to be a problem with the Orion.  What can affect both rcvrs and both ant inputs.  What have I done wrong?  
Any ideas?
Bill K4BYR