[Elecraft] Hard of hearing, almost deaf K3

[John Unger]

 A few days ago one of my K3's appeared to have suddenly gone almost deaf.
Here are some of the symptoms and observations:

- Rig's S meter shows very low or no background noise (strong stations can
still be heard weakly).
- P3 shows <S0 signal strength.
- I can hear strongest stations, they just make it to ~S1.
- Overall effect appears to be similar to having big attenuator in line.
- Problem is antenna independent.
- Rig transmits fine, low SWR, etc.
- Both main and sub receivers have the symptoms.

I've check most "obvious" things: RF gain, etc.,
(but there are a lot of buttons and MENU/CONFIG settings to inadvertently
push on the radio...)

I would appreciate any suggestions of what else to look for or reports of
similar problems from others before I ship it off to Elekraft.

73 and thanks - John, W4AU