[Elecraft] K3 - No speaker output

[Dave Hachadorian]

The speaker amp is U1 on the DSP Board.  The IC is an LM4950TS. 
The pins are very closely spaced, too close for me.

Elecraft now has an Audio Protection Assembly circuit board, Part 
Number E850506 for $2.36 plus shipping.

Dave Hachadorian, K6LL
Yuma, AZ



-----Original Message----- 
From: Stewart
Sent: Tuesday, January 14, 2014 9:36 AM
To: Elecraft Reflector
Subject: [Elecraft] K3 - No speaker output

My K3's speaker audio seems to have gone West. Audio out of the 
phones, but
nothing out of the internal speaker.

It happened when I was installing a new external speaker, a DSP 
Desktop speaker
from BHI.

Having read some recent posts about the audio chip blowing up 
because of using a
mono plug instead of a stereo one, I made sure that I used a the 
correct one.

Following guidance in the K3 users manual I connected the speaker 
to the LH
channel as I want to use my headset in stereo.

I also took the covers off and checked for the modification 
involving 470ohm
resistors. That mod was in place OK.

I switched the K3 and the speaker on and got audio from the 
speaker. However,
when I advanced the AF gain on the K3 to about 12 o'clock there 
was a pop and no
more speaker audio from the K3.

I have checked the BHI speaker with another rig and it works 
fine, so my K3 has
developed a fault.

I can't believe how sensitive it is to damage in the audio 
output, particularly
with the care I took to try and avoid this sort of thing 
happening....

As I am quite OK with SMD's I would appreciate advice on what to 
change, where
to get it and how...

Not a happy bunny !

73
Stewart G3RXQ
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