K3 Loss of Transmit Power after the KRX3 installation

[David S. Mulvey]

About a week after I installed the KRX3 Subreceiver, I noticed the K3 had lost all transmit power.

The symptoms were:

1) No RF power output
2) After the tuning process the radio did not report back the SWR
2) On the 100 watt meter scale only one bar was on during transmit
3) I could hear the relay engage as I lowered power below 12 watts
4) Fans were functioning
5) When I tried to run the Transmitter calibration routine, it failed on 5 and 50 modes with error: ERR TXG
6) The PA fuse was not thrown

When I removed the top of the radio, I noticed that the TMP cable had come loose on the KREF3 board on the J7 connector.  Replacing the connection restored TX power.

Kit builders note: When adding the KRX3 the instruction manual shows how to dress the TMP cable at J7 and if you are not careful the dressing of the cable can place sufficient downward pressure on the TMP connector that over time it will dislodge itself.

I have seen a number of people reporting the same issue, so I thought I would post the fix on the forum.