[Elecraft] Power Shut Down Resolved!

[Hunsdon Cary III]

Many thanks to Mark, N2QT; John, NI0K; Bob, K2TK, and Don (of course), W3FPR for pointing me in the right direction to solve this problem!
The reason for the power shutdown?  The ground (black) connector in the DC power cable was not locking in place and causing an intermittent high current that shut the K3 down quickly - that fail safe feature works wonderfully!  In fact, the black ground connector won't lock in place so I will order a replacement set.  When I substituted my K2 power cable, the problem disappeared.

I know there are many that are fans of the Anderson Powerpole connectors but I am not one of them!
My thanks to the hams listed above who helped me resolve this pesky situation!
73. 
H. Cary, K4TM
LYNCHBURG, VA
h3cary at gmail.com