[Elecraft] K1 went silent after 2 months

[Rod N0RC]

Bruce,

The <1 volt at the switch explains all the other symptoms. Something is
short the 12V supply to/near ground. You don't mention your K1's
configuration, so.... the first thing I would do is pull out all the
option PCBs: tuner, band module, NB...__everything__. Then make your
voltage measurement again.

Is 12v still dropping to <1V?

Y) Trace the 12V line looking for shorts and/or bad parts. You might
have to pull components to isolate various stages from the 12V supply
line. For example, pulling T4 from the board isolates the PA transistor
Q7, pulling RFC 6 isolates the Driver Q6...etc.

N) Replace option PCB's on at a time until you find the one that drags
down the voltage.


GL
73, Rod N0RC



----- Original Message ----- 
From: <BruceVasey@aol.com>
To: <elecraft@mailman.qth.net>
Sent: Saturday, September 20, 2003 9:48 AM
Subject: [Elecraft] K1 went silent after 2 months


> I am having a problem with my K1 (s/n 1673).  I completed construction
> mid-July and everything seemed fine until yesterday (9/19/03).  I was
checking SWR
> with different antennas (powering off each time) and when I powered on
the last
> time, there was no audio, no display, nothing.  I did notice that the
usual
> LED/click sequence did not occur.  I also noticed that the ATTN light
would try
> to blink every 1 - 1.5 seconds.  Voltage measured at D16 (connected to
the
> power switch S1 on RF Board) is 13.75V with the switch off.  When the
switch is
> pushed on, the voltage drops to < 1V.
>
> Any ideas where I should start looking?  Thanks.