[Elecraft] K2 - Problem with KAT2 installation

[Peter Barville]

Folks

I'm hoping somebody might be able to point me in the right direction, so 
thank you in advance for reading this.

My K2 is serial number 573, so you can see that that I built it many 
years ago. Similarly, I built and incorporated the KAT2 Antenna Tuner 
almost as many years ago. However, the KAT2 has not been used for a long 
time, as I later moved on to installing the 100W PA lid.

Although the KAT 2 was working fine when I last had it in the K2 (must 
be a good few year ago), when I came to replace the 100W lid with the 
KAT2 (and battery) lid yesterday I discovered there is now a problem 
with the KAT2.

With J8 securely and correctly mated with P4 on the K2 Control Board, 
the rig will not power up properly. After an extremely brief burst of 
(probably normal) sound from the speaker, the S Meter goes to full 
deflection, and the rig goes silent. It is as if the rig is in Tx mode, 
although there is no RF output.

I can access the KAT2 related items in the menu but, unless KAT2's J8 
is disconnected from P4, the rig will not power up correctly.

I am not aware of any mishap having occurred to KAT2 whilst it resided 
mounted in its lid, but stored away in a box, but wonder whether anybody 
has any suggestions as to where first to look?

Many thanks.

73 Peter G3XJS