In the last couple of months I diagnosed and fixed a problem with the KPA100. 
There were two failures -- one was U6 -- EL5146C which was shorted internally 
and kept the KPA100 microprocessor from receiving the +5 volts it required. The 
second were failures in the 1N5711 Schottky diodes D16 and D17 -- they failed 
as partially working.

I recently operate the K2/100 during the CQWW RTTY and it didn't give me any 
trouble. However, today I got into the shack to work a couple of contacts at 
lunch, and I'm greeted with Info 080.

A little more background -- even after fixing the issue, I would occasionally 
see an "not inst" error when pressing the Ant 1/2 switch. Sometimes the KAT100 
wouldn't light up immediately when switching the K2 on. When it did this, I'd 
generally see the "not inst" problem. Cycling the power switch would generally 
cure the problem.

I saw this issue once before, right before Field Day. I'd set up my rig in my 
camper, and then the next morning it gave me Info 080. At the time, I believe 
part of the problem was due to humidity. If I leave the rig on, eventually the 
problem seems to resolve itself.

There's something that definitely seems to be sensitive to humidity and the 
action of the AUXBUS. 

As I write this, it is 75 degrees F and 87% humidity in my unheated storage 
room shack. The K2 initially had several segments in the display that were only 
partially dark, but now they are dark black. Initially, there was no sound out 
of the speaker, and it would "tick" when I turned the main tuning dial. Perhaps 
if I wait long enough, it will eventually dry out.

Any clue how to diagnose this problem? Are there components which are 
particularly sensitive to humidity? Why does this affect the AUXBUS operation?

Any help or suggestions would be greatly appreciated.
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