I'm stumped.  I just finished the LO section.  After the first section (power 
supply) All was well.  3.3v and 5v were solid.  Current draw perfect.

Current draw with resistor in LO section was right on.  HOWEVER now I can only 
measure .7v at 3.3 rail and U4 becomes VERY! hot.  Further, voltage at U5 
measures 5v coming in on the two outer pins on input side and .7v on both pins 
on output side. (go figure)

All switches on SW1 set to 0.  U6 in properly.  SI570 appears to be soldered 
perfectly under scope.  No visible solder bridges top and bottom.

What the heck????

Dohn  N8EWY

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