Check the Berg end of the controller cable - make sure
you don't have
any disloged pins or wires that are pulling out of the crimp pins...
those ends are somewhat fragile (compared to IDC-type flat cables),
and I've seen some mechanical abuse.
Okay, that's at least part of the problem. The red wire that connects
near the end of the connector marked AB is broken. Looks like it will
be difficult to fix since part of the connector seems to be glued
together as well as tie wrapped together.