[Elecraft] K3 - communication failure after KIO3B upgrade

[Carl Clawson]

Maybe the combined wisdom of the group will be able to help before I send
this to Elecraft support.

I installed the KIO3B upgrade in my K3. The USB interface from PC to K3
works but only if you don't plug a cable in the RS232/P3 jack. The RS232
connection to the P3 isn't happening -- no frequency info or VFO cursors
are displayed. Just hooking it up causes communication with the K3 to fail.
Even if the connectors to the P3 are left unplugged, simply plugging the
cable into the RS232/P3 jack causes communication to fail. If I try RS232
mode, the PC can talk to the P3 with the P3 utility, but cannot talk to the
K3.

There are some slightly different symptoms, depending, so here's more:

1. USB mode, CBLP3Y plugged into the K3 jack but not plugged into P3.
Starting the K3 utility yields the message "K3 waiting for firmware load."

2. If I plug the Y cable into the P3 and start the K3 Utility, it cycles
through baud rates and never sees the K3. The same happens if I use RS232
mode and connect the PC to the P3 and the P3 to the K3 with the
single-headed cable.

All firmware and utilities are up to date and I've double and triple
checked all the settings I can think of. I even re-opened the top to double
check the USB/RS232 switch on the KIO3B.

Any suggestions? I'm thinking that my digital IO board might be faulty.

Thanks,
Carl WS7L