[Elecraft] KPA 500 not turning on every time

[Howard Sherer]

I have had this problem since the my KPA was new 7 months ago. 
Occasionally it would not turn on when the on button was pushed, you had 
to cycle the rear power switch and then the on button would turn on the 
KPA. This problem has gotten much worse and now occurs about 50% of the 
time.

Is this a known issue and is there a fix?