[Elecraft] Is the K2 cable to the computer the same as one for the K3?

[Philip L. Graitcer]

I am using a built according to the manual K2 cable between my K3 and  
USB/serial port adapter/computer. It "seems" to have good  
functionality, except I can't use the Function keys in the N1MM logger  
to send code. I suspect it might be that jumper that was in the K2  
cable.

If the K2 cable is not compatible for the K3, can I make it that way  
(since I have an extra).

Or do I have another problem?