Hacking the Xbox

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Hacking the Xbox: An Introduction to Reverse Engineering
The Anatomy of an LED
LEDs, or light emitting dodes, are polarized devices, which only
allow current to flow in one direction. This means that they will
not work when put in backwards. Figure 3-9 illustrates the
anatomy of an LED. The shorter lead on the side of the LED
package with a small flat is called the cathode. The cathode
must be connected to a potential more negative than the
other lead, the anode, in order for the LED to function.
Figure 3-9: The anatomy of an LED.
flat mark
(most cases)
shorter
lead
cathode
(negative)
Differentl LEDs characteristically require a different amount of
forward voltage to turn on. Red LEDs typically require 1.7 volts,
green LEDS require about 2.1 volts, and blue LEDs require 3.5
volts and up. Early blue LEDs required almost 5 volts of forward
voltage, but advances in technology have decreased
their voltage making them easier to integrate into batterypowered
and low voltage electronics. When shopping for an
LED for this project, be mindful of the required forward voltage.
If you install a 5 volt blue LED, its light output will be very
dim, since the maximum forward voltage generated by the
Xbox drivers is around 3 volts.
solder to wet the blue LED’s leads and the metal stub on the circuit
board assembly. If this does not happen, remove the iron and apply a
little bit of flux to the joint, and try again.
Do not hold the soldering iron tip against the metal stub for extended
periods of time or it will melt the solder that holds the stub in place.
You will know that the stub’s solder joint to the board has melted, when
the stub starts to sway freely. If this happens, hold the soldering iron tip
against the board and slowly drag the soldering iron tip away. Dragging
the tip will prevent the stub from getting pulled out of the board with the
iron. Wait for the stub to cool and bend the stub back into position.