[Elecraft] K2 Shuts Down Immediately after Turning Power Switch On

[Michael Eberle]

I hooked up my K2 this morning and everything seemed to be working 
fine.  I have the K2/10 with the KAT2 in one box.  I built the KAT100 
and KPA100 in the EC2 enclosure.  With the K2/10 connected to the 
KPA100/KAT100, I hooked up an antenna and initiated a TUNE on 40 
meters.  It started tuning and in the middle of the tune, everything 
shut down as if I had turned the power swtich off.  I tuned the power 
switch off and back on again and now it will only power up for about a 
second and immediately shut down again.  I disconnected the K2 from the 
KPA/KAT box and with nothing connected but power to the K2/10 it still 
does the same thing.

I disassembled it and checked Q7 and Q8 which do not appear to be 
shorted.  The collector voltage on both initially reads 10.8 volts at 
power up until it shuts down and then drops to about 0.8 volts.  The 
base voltage on both of them is at about 0.55 volts.

Where should I go from here?

Thanks,

Mike - KI0HA