[Elecraft] No output - internal spkr - K2/100

[Dohn]

Thanks Don,

I feel a little more comfortable with these concepts each time I have to
work through them.  I was pretty certain of the area look over and I knew
(hoping) it was one of those jacks.  Going to start digging.

Thanks again to everyone,

Dohn  N8EWY 

-----Original Message-----
From: Don Wilhelm [mailto:w3fpr at earthlink.net] 
Sent: Saturday, February 10, 2007 4:26 PM
To: Dohn; elecraft at mailman.qth.net
Subject: RE: [Elecraft] No output - internal spkr - K2/100

Dohn,

With headphones OK, but speaker not working, there are 4 things to check.
First, check to see if you mistakenly plugged the speaker into the P5 header
on the control board - the speaker plugs onto the RF Board.

Second, have the crimp pins in the speaker connector been pushed back into
the housing?  The pins must be inserted properly and will lock into place if
done correctly, many builders have trouble with inserting the pins.

Third, is the speaker cable wired backwards?  On the QRP top, the copper
wire should connect to pin 1 of RF Board P5 and the non-grounded lug of the
external speaker jack - the KPA100 is opposite in that the tinned wire is
connects to P5 pin 1 and the non-grounded side of the AF path on the KPA100
board.

Forth, check the soldering of the headphone jack, especially the 3 pins
toward the back (these are the switch contacts.

If you think the headphone jack switch may defective, you can check the
resistance from RF Board J8 pin 7 to RF Board P5 pin 1 - this path should
measure close to zero ohms with the headphones removed (if the headphone
jack switch is OK).

Since your speaker 'just quit' after it was working, I would think the first
3 items may be OK,so check the 4th one first - check the soldering first and
then do the continuity check.

73,
Don W3FPR

> -----Original Message-----
>
> Howdy .. My real problem is that when there are no headphones plugged into
> the front and nothing hooked to the "ext spkr" in the back I'm not getting
> anything through the onboard spkr in my K2/100.  This is true of
> the spkr in
> the QRP lid as well when swapped out.  This happened suddenly
> last evening.
> The internal speaker was working fine, and then I noticed it
> wasn't working
> later in the evening.
>
>
>
> The "ext spkr" is producing no audio now.  This is true of the KPA top and
> the QRP top.  The lack of audio in the internal speaker  and the
> "ext spkr"
> jack in the back are tied together I'm sure.  I get a nice
> waterfall in say
> HanScope when the audio is taken from the headphone jack in the
> front of the
> K2/100.  If I then switch back to the "ext spkr" in the rear there is no
> sign of audio present in the HamScope waterfall. No audio at the internal
> speaker on the way up to plug into the rear ext spkr jack either.
>
>
--
No virus found in this outgoing message.
Checked by AVG Free Edition.
Version: 7.5.441 / Virus Database: 268.17.33/678 - Release Date: 2/9/2007
4:06 PM



-- 
No virus found in this incoming message.
Checked by AVG Free Edition.
Version: 7.1.411 / Virus Database: 268.17.33/678 - Release Date: 2/9/2007