[Elecraft] K2 Alignment & Test, Part II PLL problem, Continued

[rootboy at bellsouth.net]

Just an update:

Following the advice that I had found on this list, I desoldered the crystal and checked for solder balls. It was clean. 

I also checked the voltage on pin 5 of U6 and it was 4 volts.

I looked at the thermistor board and it looked good. 

I watched the signal using a scope and with the radio setup for the "CAL FCTR" test, 
I had a reading of ~400hz and nothing but noise on TP3.

Once I pressed the "BAND - " button, I got the expected 12,090hz signal and a reasonably pretty sine wave on TP3.

Pressing the "BAND +" or turning the tuning knob would send it back to ~400hz and the signal would revert to noise.


Any thoughts?