[Elecraft] Intermittent to no receive or xmit

[Craig Taylor]

I purchased a pre-built K2 a couple of years ago.  It seemed to work fine except on occasion it would stop receiving, with a tap on the right side of the cabinet it would be okay.  These taps became more frequent.  I also noticed that the K2 would not transmit at these times.  Finally, about a week ago it quit.  Where should I look, or what should I do to get the rig back on the air?
 
Thank you,
Craig K9CKA