[Elecraft] K2 - keypad problem

[Don Wilhelm]

Mike,

You have a pushbutton that is 'stuck' for one reason or another.  It may 
be a mechanical problem or it could be electrical.
I am making that judgment because the display you report is exactly what 
is supposed to happen if you hold a pushbutton down while powering the 
K2 on - the fact that the pushbutton continues to be held down (either 
physically or electrically) results in the inability to do anything else.

You can find out which switch in the pushbutton matrix is causing a 
problem using an ohmmeter.  Check from front panel U3 pin 6 to each of 
U2 pins 3, 4, 5, 6, 11, 12, 13, and 14.  If you find no path with low 
resistance, the problem switch is not in the  Bank1 set, so check Bank 2 
- check continuity from U3 pin 16 to the same pins on U2.

If you find no pushbutton that is closed, check the soldering at RP1 
carefully - these resistors act as pullups, and a missing pullup 
resistor in the circuit can act just like a closed pushbutton.  As a 
double check, measure the resistance from each of the U2 pins mentioned 
above to the 5A voltage rail (U2 pin 16 is one location) - you should 
measure 100k ohms in all cases.

73,
Don W3FPR

Michael - VE3MKX wrote:
> Hi All,   Im new to the group, I have a K1 #744 and just finished installing the KAT1 - Works great, what a rig !
>
> So this is what I have....
>
> I bought a K2 #4436 that was started by a ham who did not have the time to finish it.  
>
> He managed to get to page 39 of assembly.  When I bought the kit, I was not sure where he exactly left off, and so on,,,, So I went thru several procedures spending a couple hours checking his work, going through the resistance check sheet charts.  All looked good.  All three charts checked out to be fine.   His work looked good.
>
> I continued building the kit and now I am stuck !    I made it to page 42.   Yes, a whopping 3 pages !  ;)
>
> Problem.  Once the kit is turned on, 'Elecraft' shows up on the screen,  then ' 204p  109 ' shows up for a brief second, the rig then displays the 7.100.   I then press the display button - nothing,  I try all the other front panel buttons, nothing. The main tuning dial does work and the display is fine.
>
>