[Elecraft] K2 Display Board not Responding.. cont

[Jason Hissong]

Hi guys,

I wrote earlier about my K2 appearing to be "stuck" after I power it up 
for Test 1.  The symptom is that it appears to turn on ok, relays latch, 
"Elecraft" appears, and 7100.0c displays.  However, none of the buttons 
or encoder seem to work.

I did some checking.  I think I may have ruined U3 on the display board 
because I put it in backward and desoldered it to put it in right (when 
I was assembling the display board).  I think when I was desoldering it, 
I got the chip too hot, thus ruining it.

Reason why I think this is because I can push on U3 with my finger and 
the LEDs and the backlight come on (all of the LEDs in the S meter).

I wanted to make sure that I did not ruin any of the pads so I did a 
continuity check between the back of the board and the chip legs which 
check out ok. I do remember leaving an indent on the top pad for pin 
number 1 of U3.

Would U3 being screwed up basically make the display board not register 
any button pushing and encoder movement?  The LCD works 100%.

Is there a way to see if signals are coming out of the proper pin?  I am 
new to troubleshooting this stuff... (I usually debug software.. not 
hardware :)

Thanks!

Jason Hissong
N8XE