[Elecraft] A broken K3 #378 K1WHS

[Keith Trinity]

Hi Dave;
That old of a K3 could have tin pin oxidation on the front panel pins (we
change them to gold).
Try removing the top 3 and bottom 2 screws and gently pry in the bottom
slots just a quarter inch, then shove it back on. See if that fixes it.

Also, tap DISP and rotate B to see the PLL1 voltages (Tech mode must be
on).
Go thru the bands watching the voltage, it should vary and be several
volts. If you swap synthesizers, you might need to run the VCO cal, see
manual for config item "VCO MD".

Are you on Ant 1 or 2? (if KAT3 equipped).

Did the radio get reset by accident? If so, the filters etc need to be
setup, or load an old config file with the K3 Utility.
If that radio has not been here, it will need a LOT of updates!!
Suggest sending it in.
Keith WE6R

From: David Olean <k1whs at metrocast.net>
To: Elecraft Reflector <elecraft at mailman.qth.net>
Cc:
Bcc:
Date: Tue, 24 Mar 2020 16:57:52 +0000
Subject: [Elecraft] A broken K3
For all you tech gurus,

I am trying to fix an old K3 that belongs to my brother. He has serious
medical issues and I was hoping to fix his K3 so he can use it and be on
the air in between chemo treatments.  He is very isolated and a working
ham rig would be a big help to him. I am not having much luck with tech
support with all the virus concerns and work disruptions. Here is what
is happening in his K3 SN: 378

No receive or transmit. I hear no band noise, just a bit of hiss with
the volume turned to max. He was in the middle of a QSO and it just
died. When you transmit, it acts like it is transmitting but there is no
output. The digital readout indicates a frequency and it changes as you
turn the big knob, but the K3 hears nothing and transmits nothing. If
you change bands the rig changes bands and all looks OK as to frequency
readout etc. I hear all the relays clicking, but no RX or TX anywhere.

I see a 8.23 MHz signal at the RXIF  cable on the RF board (J-81) from
the KREF board. It is about  100 mv p to p.

I do not see any signal on the TXIF  cable going to the RF board (J-65)
from KREF board.

I checked at Pin 2 on P73 (The synthesizer) for any RF output from the
VCO and I see nothing except some suspicious DC fluctuations that
amounts to a jump of maybe 100 mv. It looks random and not normal.  I
should see several volts of RF here I think!

I do see the 49.380 MHz signal in the KREF board. (J1 & J2) That part is
working normally.

This is telling me that I have a synthesizer problem. Are there things
to check on the Synth board?  Is there any typical failure mode that has
shown up?  Are the boards repaired, or must I buy a new synthesizer
board?  This is an original synthesizer board, not a new design K3S board.
 I have been waiting for days to get any tech support response.
 Any help would be appreciated.
 73 Dave K1WHS