[Elecraft] K2 Display Board not Responding.. cont

[Harry Yingst]

"I can push on U3 with my finger and 
the LEDs and the backlight come on"

??????

Is the chip loose?




--- Jason Hissong <jhisson1@columbus.rr.com> wrote:
> 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
> 
> 
> 
> 
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=====
Harry - AB2PN

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