[Elecraft] K2 VCO, wrong frequency

[Bill Coleman N2BC]

I'm building K2 #5290.  Have made it through the second session on the 
RF board (Assembly Part II).  The VCO freq is wrong....

The PLL Ref Osc range is 12098 to 12084. I'm seeing a stable 12445 on 
the VCO (TP1), VFO set for 4000.1.

I've eyeballed the RF board carefully with a magifying lens & didn't 
find anything conclusive.  I looked at U4 with a scope and am not sure 
if I'm seeing my bug, have my setup wrong, or the voltage chart is wrong.

U4 pin 5 (SDO) is zero and goes high (+5) with pulses on band +/- 
(measurement chart says +5)
U4 pin 7 (SCK) is +5 and goes low with pulses on band +/-  (measurement 
chart says 0)

Given that the MCU can 'move' the PLL Ref Osc, that pretty well says 
that the SDO and SCK lines are OK, right?

All the rest of the pins on U4 look reasonable per the measurement chart. 

I've double checked L30, T5, D23-D26

I suspect I'm barking up the wrong tree with the SDO and SCK lines...   
Where next?

Thanks!   73, Bill  N2BC

PS:  My first big kit was an SB-100 in 1965 I think.  It's first power 
on was much more dramatic than the K2. Smoke curling up from the 
chassis. A hunk of miniature coax carrying low B+ was shorted.  That's 
when I figured my homebrew power supply should probably have some fuses....