[Elecraft] [K2] Friends K2/100 problems?

[Curt]

 Friend experienced the following with his K2/100.

"Turned the K2 on, but I had no transmit, just the receiver being muted but 
nothing else. I checked the mic on another radio and it was fine, so somehow 
the K2 died while not being used, go figure."  Two hours later...

"I just got home and tried the cw mode, it worked fine. All the controls 
seem to function ok as well, so another project for the pile." One hour 
later:

"Here's an update as of 4:05pm, it now works ok. I ran up to 20 meters, from 
the 40m where we were this morning, and tried the mic, it was fine, so I 
went back to 40m, it then worked. I'm thinking a relay was stuck, maybe, if 
so it will happen again."

Any thoughts?  Are the relays in these radios prone to failure just sitting?

73, Curt KB5JO