Need a little SMD help!

classic Classic list List threaded Threaded
4 messages Options
Reply | Threaded
Open this post in threaded view
|

Need a little SMD help!

.k8dd.-2
I need a little help with replacing the two SMD diodes in the VSWR circuit.  

K3 support has determined, after 4 days of emails, that they are bad - possibly from a 'nearby lightning strike' - and it's up to me to replace them with 2 new more robust diodes or pay for having them replaced if I send them the K3.  I guess the new robust parts are warranty, but replacing them isn't!

Elecraft is sending me the 2 new more robust diodes.   I do not have the equipment to remove the old ones and replace them, nor do I have the desire to work on anything smaller than a 1/8 watt resistor.

So ..... is there anyone within 50 miles or so of Lapeer, MI who can change these new diodes when I get them?    And if you don't have a K3, this would be a good chance to see one and try it out!

73    Hank    K8DD

_______________________________________________
Elecraft mailing list
Post to: [hidden email]
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
 http://mailman.qth.net/mailman/listinfo/elecraft

Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com
Reply | Threaded
Open this post in threaded view
|

RE: Need a little SMD help!

Dave Van Wallaghen
Hank,

I'm around 50 miles south of you and would be happy to help you out if you
can make the trip. I've made a couple of mods to my K3 already, so I have
some experience with it.

Contact me offline if you are interested.

73,
Dave W8FGU

> -----Original Message-----
> From: [hidden email] [mailto:elecraft-
> [hidden email]] On Behalf Of hank k8dd
> Sent: Thursday, August 14, 2008 4:46 PM
> To: [hidden email]
> Subject: [Elecraft] Need a little SMD help!
>
> I need a little help with replacing the two SMD diodes in the VSWR
> circuit.
>
> K3 support has determined, after 4 days of emails, that they are bad -
> possibly from a 'nearby lightning strike' - and it's up to me to replace
> them with 2 new more robust diodes or pay for having them replaced if I
> send them the K3.  I guess the new robust parts are warranty, but
> replacing them isn't!
>
> Elecraft is sending me the 2 new more robust diodes.   I do not have the
> equipment to remove the old ones and replace them, nor do I have the
> desire to work on anything smaller than a 1/8 watt resistor.
>
> So ..... is there anyone within 50 miles or so of Lapeer, MI who can
> change these new diodes when I get them?    And if you don't have a K3,
> this would be a good chance to see one and try it out!
>
> 73    Hank    K8DD
>
> _______________________________________________
> Elecraft mailing list
> Post to: [hidden email]
> You must be a subscriber to post to the list.
> Subscriber Info (Addr. Change, sub, unsub etc.):
>  http://mailman.qth.net/mailman/listinfo/elecraft
>
> Help: http://mailman.qth.net/subscribers.htm
> Elecraft web page: http://www.elecraft.com


_______________________________________________
Elecraft mailing list
Post to: [hidden email]
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
 http://mailman.qth.net/mailman/listinfo/elecraft   

Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com
Reply | Threaded
Open this post in threaded view
|

Re: Need a little SMD help!

Don Ehrlich
In reply to this post by .k8dd.-2
Hank,

Sorry that I am not a little closer.  However, I recently replaced my diodes
(using the SMT parts .. but the leaded types will install just as easily)
and the only tricky part is getting the old ones off of the board.  I
received a lot of advice from the list and the method I found easiest is
described below.

First .. I want to note that the SMT diodes that are installed originally
have three solder tabs but one of them is a dummy with no connection.  Also,
those the bodies of those SMT parts are slightly elevated off of the board
.. the space is too small to be visible but it is there (at least it was on
my board) and it came in handy when lifting the old parts.

I was advised to heat the diodes evenly using a large blob of molton solder
on the tip of my iron and touching the top of the diode with the hot solder
blob.  That did not work, perhaps because my soldering iron tip was not big
enough.  Then I tried slipping a very very thin piece of steel sheet under
the diode while heating first one side of the diode and then the other.  The
perfect piece of thin steel is a  0.002 feeler gage that is part of an
assortment of feeler gages used by mechanics for setting spark plug or valve
lifter gaps.  Many of us have them in our tool box.  That feeler gage worked
very well because it nested under the edge of the diode before I had touched
it with the iron and it lifted the diodes easily leaving the pads looking
like new.

For what it's worth ...

Don K7FJ


I need a little help with replacing the two SMD diodes in the VSWR circuit.

K3 support has determined, after 4 days of emails, that they are bad -
possibly from a 'nearby lightning strike' - and it's up to me to replace
them with 2 new more robust diodes or pay for having them replaced if I send
them the K3.  I guess the new robust parts are warranty, but replacing them
isn't!

Elecraft is sending me the 2 new more robust diodes.   I do not have the
equipment to remove the old ones and replace them, nor do I have the desire
to work on anything smaller than a 1/8 watt resistor.

So ..... is there anyone within 50 miles or so of Lapeer, MI who can change
these new diodes when I get them?    And if you don't have a K3, this would
be a good chance to see one and try it out!

73    Hank    K8DD

_______________________________________________
Elecraft mailing list
Post to: [hidden email]
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
 http://mailman.qth.net/mailman/listinfo/elecraft   

Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com
Reply | Threaded
Open this post in threaded view
|

Re: Need a little SMD help!

Don Wilhelm-4
In reply to this post by .k8dd.-2
Hank,

If you cannot get local help with it, I have successfully used the
following technique to remove SMD ICs, and it should work with the diodes.

Push a length of enameled wire (largest gauge that will fit - usually
#26 or #28) under the pin, grasp both ends of the wire, then heat the
lead and solder pad while pulling on the wire.  Once the wire slips
through, the lead will no longer be in contact with the pad - do 2 that
way and the 3rd one is a snap.

73,
Don W3FPR

hank k8dd wrote:
> I need a little help with replacing the two SMD diodes in the VSWR circuit.  
>
> K3 support has determined, after 4 days of emails, that they are bad - possibly from a 'nearby lightning strike' - and it's up to me to replace them with 2 new more robust diodes or pay for having them replaced if I send them the K3.  I guess the new robust parts are warranty, but replacing them isn't!
>
> Elecraft is sending me the 2 new more robust diodes.   I do not have the equipment to remove the old ones and replace them, nor do I have the desire to work on anything smaller than a 1/8 watt resistor.
>
> So ..... is there anyone within 50 miles or so of Lapeer, MI who can change these new diodes when I get them?    And if you don't have a K3, this would be a good chance to see one and try it out!
>
> 73    Hank    K8DD
_______________________________________________
Elecraft mailing list
Post to: [hidden email]
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
 http://mailman.qth.net/mailman/listinfo/elecraft   

Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com