K3 Serial Port Fixed!

[Paul A. Thompson]

Thanks, Elecraft Reflector friends!  Thanks to MontyS, Matt Zilmer, and
Howard Stephenson, I have the K3 serial port working once again!  Howard had
me check the voltage on pin 8 of U1 on the KIO3 main board, and it was less
than -5V (about 120 mV) with the serial cable plugged in.  This was the
first clue.  The second was that the lettering on the package of the IC
itself was discolored/faded in the center section of the IC, a sign that the
chip had overheated at some point.  In any case, replacing the U1 serial I/O
chip did the trick.  I had a friend with lots of experience at soldering and
unsoldering surface mount ICs remove the bad chip, clean up the solder pads
and tack down and then we soldered the pins of the new IC (.05" spacing, I
believe) using a micro soldering pencil.  If anyone is interested, I'll find
out and pass on the specifics of the heat gun we used for removal and the
soldering station that did such a fine job with no damage to board or
surrounding parts.  Thanks again, guys, and I should be back on the digital
modes today with HRD!

 

Oh, and once I had the info on the part no. and got it ordered, it came 1st
class mail from Elecraft within four working days. not bad.

 

73, and Merry Christmas to All, and may your dreams include visions of sugar
plums (2nd receiver board, 2 mtr xvtr, etc) dancing through your head.

 

Paul N5PT

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[Pete Smith N4ZR]

Ir's always interesting to me that these components can withstand heat
from a hot air gun that is high enough to melt solder, but I have done
this often with a heat gun made for hobby stained glass work.  It's a
lot cheaper than the professional rework units.

73, Pete N4ZR
Check out the Reverse Beacon Network at
http://reversebeacon.net,
blog at reversebeacon.blogspot.com.
For spots, please go to your favorite
ARC V6 or VE7CC DX cluster node.

On 12/19/2012 8:27 AM, Paul A. Thompson wrote:

> Thanks, Elecraft Reflector friends!  Thanks to MontyS, Matt Zilmer, and
> Howard Stephenson, I have the K3 serial port working once again!  Howard had
> me check the voltage on pin 8 of U1 on the KIO3 main board, and it was less
> than -5V (about 120 mV) with the serial cable plugged in.  This was the
> first clue.  The second was that the lettering on the package of the IC
> itself was discolored/faded in the center section of the IC, a sign that the
> chip had overheated at some point.  In any case, replacing the U1 serial I/O
> chip did the trick.  I had a friend with lots of experience at soldering and
> unsoldering surface mount ICs remove the bad chip, clean up the solder pads
> and tack down and then we soldered the pins of the new IC (.05" spacing, I
> believe) using a micro soldering pencil.  If anyone is interested, I'll find
> out and pass on the specifics of the heat gun we used for removal and the
> soldering station that did such a fine job with no damage to board or
> surrounding parts.  Thanks again, guys, and I should be back on the digital
> modes today with HRD!
>
>  
>
> Oh, and once I had the info on the part no. and got it ordered, it came 1st
> class mail from Elecraft within four working days. not bad.
>
>  
>
> 73, and Merry Christmas to All, and may your dreams include visions of sugar
> plums (2nd receiver board, 2 mtr xvtr, etc) dancing through your head.
>
>  
>
> Paul N5PT
>
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>
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>

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[Don Wilhelm-4]

There is another alternative for removing SMD mulit-legged devices, and
it is called Quik-Chip.
You apply the special flux and the supplied solder and the chip
literally "floats" off its solder traces.
One must be careful to clean up the area with alcohol - if you do not
remove all the low temperature flux and solder, the new component will
not stick to the soldering.

You can get sample packages by asking.  Google for links.

73,
Don W3FPR

On 12/19/2012 8:34 AM, Pete Smith N4ZR wrote:
> Ir's always interesting to me that these components can withstand heat
> from a hot air gun that is high enough to melt solder, but I have done
> this often with a heat gun made for hobby stained glass work.  It's a
> lot cheaper than the professional rework units.
>

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[Martin]

I seem to have the same issue with my K3 I/O board.
I have a temperature controlled heatgun and will try to solder out the
IC if it turns out to be true AND if i knew what temperature to set it
to. Anyone?

Mry xmas es hny.

--

Ohne CW ist es nur CB..

73, Martin DM4iM
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[Jim Wiley]

Before you try this on your K3, get a couple of old computer boards
(junk motherboards, expansion cards, etc) and practice on them. Only
when you can remove and / or install components from the "junk" boards
successfully should you try the same with the K3.  Just my 2 cents worth


- Jim, KL7CC


On 12/20/2012 12:03 AM, Martin wrote:
>
> I seem to have the same issue with my K3 I/O board.
> I have a temperature controlled heatgun and will try to solder out the
> IC if it turns out to be true AND if i knew what temperature to set it
> to. Anyone?

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[GARY-2]

Close. It's called Chipquik <http://www.chipquik.com/>.
Gary N6LRV

-----Original Message-----
From: [hidden email]
[mailto:[hidden email]] On Behalf Of Don Wilhelm
Sent: Wednesday, December 19, 2012 3:39 PM
To: Pete Smith N4ZR
Cc: [hidden email]
Subject: Re: [Elecraft] Surface Mount IC Repairs was Re: K3 Serial Port
Fixed!

There is another alternative for removing SMD mulit-legged devices, and it
is called Quik-Chip.
You apply the special flux and the supplied solder and the chip literally
"floats" off its solder traces.
One must be careful to clean up the area with alcohol - if you do not remove
all the low temperature flux and solder, the new component will not stick to
the soldering.

You can get sample packages by asking.  Google for links.

73,
Don W3FPR

On 12/19/2012 8:34 AM, Pete Smith N4ZR wrote:
> Ir's always interesting to me that these components can withstand heat
> from a hot air gun that is high enough to melt solder, but I have done
> this often with a heat gun made for hobby stained glass work.  It's a
> lot cheaper than the professional rework units.
>

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