[Elecraft] K3 won't shut off, turns on by itself

[Dr. William J. Schmidt, II]

Mine does the same thing except only when the PR6 (six meter preamp with the
"ON" control jumper in the correct position for the K3) control is plugged
into the ACC jack.  I surmise that that possibly D4 (the diode that was
added for the reported MOD:
http://www.elecraft.com/K3/mods/KPA3_12V_Sense_Modification_Rev_B.pdf ) is
bad... and they may have had a bad batch of them...  I've not had time to
take the radio apart and diagnose this completely.  It should not hurt the
radio to use it as is though.  What you can do is remove the fan panel (4
screws on the back) and measure the voltage at pin 11 of connector P68A
after you have turned off the radio.  If it's more than 0.6 VDC the diode is
bad.

<<<
Please help. Last night my K3 worked perfectly. Power supply voltage 14volts
and always shut off after rig.  This morning, turned on power supply, k3
turns on by itself. 
Pushing the power button only blanks the screen, display backlighting stays
on.  What can cause this, tried unplugging everything then repeating, same
result.  Please help, love 
the rig. Serial 4548.   Looking forward to your reply, Coy K3FO
>>>

Dr. William J. Schmidt - K9HZ / J68HZ/ 8P6HK/ ZF2HZ/ PJ4HZ

Owner - Operator
Big Signal Ranch
Staunton, Illinois

email:  bill at wjschmidt.com