[Elecraft] K2 Serial port problems

[Jim Purvis]

I've been using HRD and DM780 for a few months now on my new K2. It
has worked wonderfully. Suddenly I can no longer connect to the
radio.
I have checked and rechecked settings and connections. I'm using a
USB to serial adapter, but its the same one I have always used and it
works on other equipment. I have also tried a different adaper with
the same results.
The radio Com port controls the KAT100 tuner just fine. Cable
connections are all good and correct. Yes, its the 'special' cable
built for the K2 per the instructions, not just a off the shelf
serial cable. The Port is varified 'ON' using the Supplemental
parmeters. (Menu then Display)
I have upgraded (after things quit) HRD to Ver 4.0 SP3 Build 1875
with no change.
I have had the K2 apart and checked for anything out of place or
loose. Checked pin continuity to and from U4 on the PA board out
through J1 to the radio control board.
The error I get is; "Make sure your radio is switched on and not in
memory mode." Yes, it's on. I have been through the K2 manual and
find no ref to 'memory mode' other than store and recall a frequency.

So before I really dig into the radio with a meter and a scope can
anyone tell me more about 'memory mode', has anyone had a similar
problem, and any other suggestions.

I will be cross posting this on the HRG Group also.

Tnx
WA7HRG