[Elecraft] A broken K3

[David Olean]

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