[Elecraft] K2 Q11 Repeated Failure

[Alan Whitman]

I have searched the archives in vain for an answer (might just be my
limited knowledge, however).  My K2, which had been operating
properly as a basic 10W, CW only with only the 160/RX antenna option
installed, suddenly began having virtually no output on transmit. 
When I opened it up, I found that Q11 was completely split in half.

After checking everything I could, I replaced Q11 and Q12 (this was a
long, involved process).  I checked Q7 & Q8 for shorts to ground and
found them to be OK.  I applied power but did not turn on the
radio.  OK so far.  When I turned on the K2, Q11 immediately began
to smoke and burst into flames within a half second.  I turned it
off as quickly as I could.

When I checked Q11 and Q12 for short to ground I found that all leads
of both transistors were shorted to ground.  I removed the devices
and checked the pads in the same way.   Now only the emitter of Q11
showed short to ground, which is correct.

I checked Q6, Q7 and Q8 for shorts to ground.  Emitters of Q7 and Q8
show short to ground which is correct.  Q6 showed 1.5 ohms, which is
also correct.

I also found that the resistance to ground from the emitter of Q13 to
ground showed 756 ohms, even when I disconnected R63 from the junction
of R60 and R62.  I expected to see about 2.8K ohms.  From what I can
find on the schematic, there should be no other path to ground, but
I'm not sure about this.  I don't know if I should be looking for a
short or looking elsewhere.

Can anyone advise if this last measurement is correct?  Where should
I look for the overall problem if this last resistance is not the
problem.

Thanks and 73
Alan K6ZY