I cannot read or write to my IC-F3400/F5400 when using an OPC-1862 cable.

Press and hold the P1 key while turning on power. You can now read the radio (one time only).

Go to Common -> External I/O -> Option and verify the following:

Option Connector -> Mode is set to OFF.

USB Connection is set to Data Transfer.

Serial Mode is set to OFF.

If after changing these settings, the radio still won't read/write, refer to CloningProgramming Errors

16/06/2020