[Elecraft] KPA100 negative bias problem

[Neal Campbell K3NC]

Hi guys

I have an otherwise perfectly performing K2 that has inoperative CAT.  
CAT was working properly over the past 2 years so something has  
changed. I do not remember trying it after performing the latest  
KPA100 mod and firmware upgrade so it could have crept in there, but  
I have ensured that there are no cold/bridge/bad solder joints there.

In investigating, there is very little (-0.2v) on pin 8 of u4.  
Following the circuit backwards, I have nowhere near normal voltages  
over d1-d8. I have verified that the diodes are all okay, no bridges  
or poor solder connections.

Does this sound like the oscillator at X1 is not firing? Is there a  
good way to know?

73
Neal Campbell K3NC
nealk3nc at gmail.com

telnet to our DX Spotting clusters at: dxc.k3nc.com, ports 12001 and 23

"Devoted to Dogs: How to be your dog's best owner"
Great Dog Book  at www.abrohamneal.com