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[K2] Control board booboo?

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Wayne Conrad

[K2] Control board booboo?

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

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Don Wilhelm-4

Re: [K2] Control board booboo?

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.
--------------------------------------------------------------------------------------
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
>
>

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Wayne Conrad

Re: [K2] Control board booboo?

Don, Thank you. And thanks also to Alan Price and Bill Coleman for
their help off the list.

You're right that it's R12 and not R18. Good catch.

Both sides of the "booboo" resistor have continuity to the appropriate
places. On the side with the lifted pad, to P2/10 and P4/10. On the
other side, U6/2.

Would it be a good idea to reheat the solder and push the pad down?

I will turn the iron down in any case.

Wayne Conrad

On 04/16/2011 06:33 PM, Don Wilhelm wrote:

> 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.
> --------------------------------------------------------------------------------------
>
> 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
>>
>>
>

Don Wilhelm-5

Re: [K2] Control board booboo?

Wayne,

For the sake of neatness, you can heat the solder pad and put it down
onto the board, but since all the connections are intact (I could not
see a trace in the image going away from that pad on the top side of the
board), it does not matter - the solder pad on the top of the board is
only a "place holder" that makes no connection on that side. Solder
pads that have no traces leaving from them are especially easy to lift
if too much heat is applied (but that does not usually happen if there
are traces leaving the pad on that side). Turn your iron temperature
down a bit.

73,
Don W3FPR

On 4/16/2011 9:42 PM, Wayne Conrad wrote:

> Don, Thank you. And thanks also to Alan Price and Bill Coleman for
> their help off the list.
>
> You're right that it's R12 and not R18. Good catch.
>
> Both sides of the "booboo" resistor have continuity to the appropriate
> places. On the side with the lifted pad, to P2/10 and P4/10. On the
> other side, U6/2.
>
> Would it be a good idea to reheat the solder and push the pad down?
>
> I will turn the iron down in any case.
>
> Wayne Conrad
>