The actual R3 trace is on the bottom of the board, and only the top connection is needed. That little short trace there just goes to that Resistor, a 100k Pull-Down on the R3 line. If that bit or trace is broken so the Resistor is no longer in circuit R3 will not work correctly.
Clean all of that up with a Q-tip and some rubbing alcohol, then reinstall the Stick first and see how it acts.