A resistor is used to lower the amount of current from a source of electricity into a level usable by the LEDs. You will need to use ledcalc
to know what resistor you need for your setup. Different color LEDs can have different voltages. Some reds are 2.0 volts, some blues are 3.4v. If you use the same resistor for four different colored LEDs, some will be bright and others dim. If you can get all of the LEDs to have the same power requirements, great.
The best source for power in an Xbox Controller is the red 5v power source. My RGB LEDs require 3.4v and 25mA each. Parallel is used to minimize the amount of wires and resistors needed for an install, by placing more work on a single resistor (Meaning we need a higher maximum wattage rating for the resistor, but in the case of 5 LEDs it doesn't really matter). You can also use series for wiring, or each LED receiving its own resistor.
For my install, I required an 18 Ohm, 1/4 Wattage resistor as told by ledcalc
(This is for a 5v supply, four 3.4v 25mA LEDs in parallel). The wattage rating is the maximum amount of heat the resistor can give off, you can have a far higher rating than required and still be fine, just don't overload the resistor.The Power Source
If you look at where the controller cable attached to the mainboard, you will see many colored wires. Find the red wire (which should be at the bottom) and follow the pin to the other side. We will solder our resistor to this solder point.
With the needle nose pliers bend your resistor into shape, tin the end of it, and attach it to the solder point on the mainboard.Wiring the Wires
As all of the positive wires have been soldered together, cut a large length of wire (6 inches) and solder it to the positive bundle. Mine is colored white, and has been attached to the other end of our resistor.
The black bundle should receive its own wire as well, only it will be wired to the negative solder point where the black wire comes through the mainboard (shown in picture).Testing
You should now be able to plug the controller into the console, turn it on, and everything should light up!