[Elecraft] K2# 1068 stuck in transmit mode

[Don Wilhelm]

Bill,

It may be time to drag out the schematic and ohmmeter to see what if the
DOT/PTT line has a short to ground.  You can check at Control Board U6 pin
30, but that may not be where the trouble is.  If you find no short with the
ohmmeter check, then try it with power on - you should find both U6 pin 30
and U6 pin 29 at a high level (near 5 volts).

If all the above is OK and it still is in transmit mode (turn the power
control to minimum and be certain you have a dummy load connected), check
pins 27 and 28 of U6 - pin 27 should be at a low level when the uP is trying
to receive and pin 28 should be high - if they are the other way around,
then the uP is telling the K2 to transmit and the problem is inside the uP.

Let us know what you find and we can go forward from there.

73,
Don W3FPR

> -----Original Message-----
>
> Wow.  I am still puzled over this one.  Everything under the hood looks
> good.  Sometimes it is easy to get a visual on an obviously blown
> component,
> but I see absolutely nothing amiss.  Even passes the sniff test!  The
> problem exists even with no microphone or key plugged in.  Any of
> you all K2
> gurus have any notions on this?  I did try a reset of the K2, but that did
> not make a difference other than giving me an Info 201 code and
> resetting my
> displayed frequency and mode to 7100.00c .   Again any help or suggestions
> appreciated.  Thanks Mike for the previous suggestion.
>
> 73,
> Bill Allen - WA5PB
>
>