[Elecraft] [KX1] - Display dead after 30m/80m install

[David Wilburn]

I'm helping a friend troubleshoot a KX1.  Unit was fine after build. 
Took unit apart and installed 30m/80m.  Then 3rd digit did not work on 
display.  He re-flowed some pins on the unit (I do not know which ones 
and he does not recall) and now the display is not functional at all.

I started him checking through the resistance checks on page 26 of the 
  document.  Pins 1 & 20 of U1 has about 500 ohm on it, whether U1 is 
installed or not.

We have been all through the voltages with D3/D2, U8, and U9.  All the 
  regulators seem good.  Though I did caution him about running from a 
wall wart.  His 12v seems a bit low.  Around 11.5v.

As a result of this, the voltage on pin 4 of U1 is a bit low at 3.5v. 
  Also pin 14 is at 2.5v where it is supposed to be low.

I find little odds and ends here that are not right, but if the 
display is not functional I would expect bigger issues.  Some voltage 
off on clock inputs wouldn't seem the culprit.  Also the ATU was not 
plugged in.

We have worked through the troubleshooting tree, problem 00,  I need 
to review with him where he is on problem 20.  We looked through 
problem 26.  No pins are bent on U1.  All of the voltages were good 
except the 2 mentioned.

I have not built a KX1, but built a K2.  My thoughts are to go through 
the various resistance and voltage checks for the 3 build sections and 
see if we can make any sense of it.

Am I headed in the right direction?  Am I missing anything obvious 
since I am not familiar with the KX1?

I'm hoping my friend (John, K6OWD) got setup on the list today.

Dave Wilburn
NM4M
K2/100 S/N 5982
K3/100 S/N 766