[Elecraft] [K2] Control board booboo?

[Don Wilhelm]

  Sorry, I got the subjects mixed up - ignore the subject line on my 
last post,  The proper subject is in this post and the text is copied 
below.  Sorry for the excessive bandwidth and any confusion I caused.
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Wayne,

It looks like somehow the plated thru-hole was damaged somehow - that is 
unusual, but you proved it can happen.  From your photo location, It 
looks to be R12 instead of R18.  R12 is an 820 ohm resistor, R18 is just 
a jumper wire.

Looking at Tom Hammond's board images (available for download at 
www.n0ss.net), that you are OK - solder it on the bottom side (same side 
the resistor is located).

Just to make sure the entire network is intact, after soldering it (on 
the bottom side), use your ohmmeter and check for continuity from that 
lead to P2 pin 10, P4 pin 10, and the non-grounded side of C11 - put one 
lead on R12 and the other lead on the points mentioned.

Just for completeness, check the other side of the resistor too - it 
should show continuity to U6 pin 2.

If all those checks are OK, then you are "good to go" - if any of them 
fail, you can use wire to connect the points that have no continuity - 
all is not lost, it can be repaired.

If that solder pad lifted by just inserting the resistor lead, then the 
thru-plated hole may have been defective (very unusual), but if the pad 
lifted when you attempted to solder it, take note and turn your 
soldering iron temperature down, it was too hot.

73,
Don W3FPR



On 4/16/2011 8:00 PM, Wayne Conrad wrote:
> Please see this picture:
>
>       http://yagni.com/ephemera/k2/control_board_booboo.jpg
>
> I've just soldered R18, which is on the back of the K2 control board.
> This picture is of the front of the board.  Right in the middle of the
> picture is one of R18's leads, and encircling that lead, a tilted white
> ring that looks like what was on the board, encircling the hole, before
> I started soldering.  It has lifted off of the board, buoyed by the
> solder, and is sitting there like a winning ring-toss.
>
> What is it?  Is it bad?  What do I do now?
>
> Best Regards,
> Wayne Conrad
>
>