ROW1 traces directly to pin 32 on the main MCU. This pin is configured as an output that is normally held low or high (depending on scan cycle).
The power switch (a 3-pin momentary switch) should connect VBAT to the enable pin of the voltage regulator. Use the diagram to find the regulator’s EN pin. If pressing the switch does not toggle EN, the switch is bad or a trace is broken. xbox 360 controller circuit board diagram