Xbox Power Trace Repair
A problem often encountered in early versions (v1.0 and v1.1) of the original Xbox is that the trace which carries the power-on signal from the power button to the PIC chip becomes corroded, breaking the trace. Other nearby traces may also be affected, such as the eject button and the front panel LED, but usually the power trace is first affected. If the problem is caught early, you may be able to scrape the corrosion off of the trace, but if the trace has been completely severed, you will need to solder in a bypass wire.
Symptoms associated with a broken power trace include
- The Xbox powers on as soon as the AC power cable is inserted.
- The power button does not work, either to turn the system on or to turn it off.
- The Xbox will turn itself off randomly during gameplay.
- If you do manage to turn the Xbox off with the AC power still connected (which can be done through software such as EvoX or waiting for a random shutdown), the Xbox will eventually turn itself back on.
The first symptom you may experience, at least in my case, is that your Xbox will randomly turn itself on. If you see this happen and then go to turn the console off, but the power button is unresponsive, then most likely corrosion has just eaten through the power trace, and you should act quickly before the situation worsens.
The way the Xbox power and eject buttons work is simple to understand using the schematic to the side. When the button is not being pressed, the pin on the PIC chip (which receives the power and eject signals) is HIGH (V = Vcc). When the button is pressed, the PIC pin is connected to ground causing the signal on the pin to become LOW, and the Xbox powers on. The trace which can become corroded does not run directly from the switch to the PIC chip, but rather from the signal resistor to the PIC chip. By looking at the schematic, you can see that if that trace is broken, neither Vcc nor ground can connect to the pin, and so its state is left 'floating'. This is what causes the Xbox to power on and off randomly.