[Elecraft] IO Problem

[W3FPR - Don Wilhelm]

Mark,

Other than a bad solder connection on the KPA100 board, the following checks 
(in order of probability)should reveal the problem:
1) Broken inductor RFC6, 7, or 8; 2) negative voltage supply to pin 8 of U4 
(should be -5 to -25); 3) bad U4 chip.

Remember that the most likely failure is a solder connection.  Even if it 
has been working before, still suspect the soldering. Go over all 
connections related to the components in the lower left quadrant of the 
schematic page 2 of 2.

73,
Don W3FPR

----- Original Message ----- 

I have an unusual problem may some one can help with

My K2/100 has stopped talking to my computer.

I have tried 2 computers thinking it was the serial port but no

I redid the cable and still nothing

Finally I changed the amp lid with the QRP lid and it all works fine.

I have a KAT 100 tuner as well and the rig does talk to the tuner and 
everything on the amp and tuner works.  ie power, tune, antenna switching. 
The rig just doesnt talk to the computer.  Like I said it works with the IO 
on the qrp lid and the settings on the computers are correct and the IO is 
on on both the KIO and the K100