[Elecraft] KPA100 D13

[Hank Kryger]

Hi to the group
I am working on a KPA100, page 43 manual, here the KPA is connected to 
the K2 with the ribbon cable, power to the K2 but NO power connected to 
the KPA100.
page 43 list a series of voltage tests ""ground to test point".  my 
problem is with D13. I do not get any voltage at D13 banded end.  Also 
U4 (MA1406) pin 8 has -28V manual calls for -5 to -25 V   TP1 has 
correct result, J3+lead (red) has.03V manual calls for 0V.
During the resistance tests of the KPA100, page 41, manual  I also had 
problems with the D13 measurement.  At first I had no reading,  
reheated the connections for D13,  had first intermittent and after 
several tries the correct resistance.  When I did not get a voltage 
reading at D13, I disconnected the ribbon cable between KPA and K2, 
attempted again to get a resistance reading at D13.  This time I could 
not get a resistance reading at D13.  DMM show an open circuit.
Does anyone have any suggestions?
Thanks Hank WA9QJH