[Elecraft] kpa100 question

[R. Coakley]

My KPA100 is pretty far along.  It's mounted on the heatsink and I'm part
way through the final alignment.  All ohmmeter checks are in range but I
have a problem which I didn't find mentioned in archives.  There are several
voltage measurements made when the KPA100 is connected by only the ribbon
cable to the K2 control board.  The measurement at J3 +lead (the high
current power input) is -0.15 volts rather than 0.  (The other voltages are
OK.)  I went ahead and successfully made all the rx tests and swr null
adjustments, power calibrations and temperature calibrations, but ran into
trouble with the power supply tests.  With a 13.8 volt high current supply
connected, it acts as if there is a dead short at J3 even with the K2 off.
If I bring the voltage up, things seem OK until I get to 2.5 volts.  Then
excessive current is drawn (the K2 is still off).  All the relevant diodes
are in the right way.  Has anyone else seen this problem?  I'll do another
solder bridge search.  If anyone has other suggestions, they would be most
welcome.

73  Bob