[Elecraft] K2 / KPA100 - net shorted on KPA100 --> C31 / D13 ... failure modes ?

[OZ2BRN Brian Lodahl]

Hi there,

After 100 % flawless work with the whole K2 journey, the KPA100 and all 
the add-on modules with bell's and whistles, it seems my turn has come 
now to have a build error on # 6936, or more specificly; the KPA-100:

When doing the 2nd alignment step of KPA100, I measure all the 
resistances OK but one; The cathode of D13 seems very low resistance to 
ground and not >10 kohms as expected. I measured some 6-7 ohms.

The intial checkout in 1st alignment step round confirmed all diodes 
pass and having the expected forward and reverse voltages / resistances 
as expected, so I assume for now the Diodes are OK still.

Now I may have myself an idea to the failure mode, but can any of you 
think of other (known) failure modes to this ?

My assumption is that I have shorted out the two foil layers of 
capacitor C31; effectively putting both sides of C31 to ground - as I 
managed to nick the house of C31 with my auxillary 30W solder iron, when 
soldering the emitters of Q1 and Q2, and the plastic housing of C31 is 
now slightly open and the internal foil visible.

( and yes; I'm givin' myself a hard time and cursing my own lack of 
being careful :-) !! )

Any other bright ideas beyond the obvious C31 defect, hence replace ?

73'
Brian OZ2BRN
K2 # 6936