Hacking the Xbox

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Hacking the Xbox: An Introduction to Reverse Engineering
You can tell when liquid solder is wetting a piece of metal by looking at it. A
wetted joint looks like the molten solder has lost all surface tension; the
liquid solder is shiny and it flows smoothly over the work area. In the
opposite situation, the solder has a dull sheen to it, and it tends to ball up
around the soldering iron tip instead of flowing outward.
Use Flux
Solder fails to wet the subject metal because oxygen in the air or dirt and
grease have reacted with the metals. In this case, you can apply a flux to your
workpiece to break down these foreign compounds. The word flux comes
from the Latin fluxus, which means flowing. Most solder comes with a core
of flux built in to enhance solderability. If you look at a cut piece of solder
carefully, you can see the flux core surrounded by the solder alloy. Always use
solder with a flux core, or you will be in a world of pain trying to get the
solder to wet. Almost all solders made specifically for electronics have a flux
core, but there are solders that you can accidentally purchase in a hardware
store that have no flux, and that are made for purposes such as joining
pipes. When you heat a flux-core solder, a small puff of vaporized flux
smoke will rise up. A small fan placed near the work area will blow the
fumes away and prevent inhalation.
A common novice mistake is to have too much faith in flux-core solder.
Frequently, the flux contained in a flux core solder is not enough to get the
solder to wet. In this case, you will need to apply extra flux. Raw flux comes
usually as a liquid or a paste, so application is easy. In liquid form, a single
drop of flux can be applied with half of a toothpick. Break the toothpick in
half, leaving the break slightly jagged. Dip the broken end of the toothpick
into the flux, and a small drop will cling to the end. Applying liquid flux to
a large area can be done with a fine-tipped artist’s brush, but be sure to clean
the brush when you are done or it will end up gummy and unusable in a
couple of days. A flux dropper is also handy, but expensive. A flux dropper
is a bottle with a thin capillary needle on top; when you invert the bottle,
flux slowly drips out of the capillary. In paste form, flux can be applied by
dipping any piece of scrap, such as a toothpick or a piece of solid wire, in the
flux paste. Finally, flux pens are handy for beginners because they combine
flux storage and dispensing in a convenient and inexpensive package. Flux
pens don’t have the accuracy or quality of other flux application techniques,
but they are convenient and good for occasional use.
Many fluxes require clean-up after use. Fluxes can harden with time, making
repairs difficult in the future, they can slowly attack the board, and they can
absorb water and become conductive. The traditional soldering flux is a
resin flux. Resin fluxes require the use of strong solvents that are flammable
and toxic. As a result, I tend to recommend water soluble fluxes or no-clean
fluxes. Water soluble fluxes can be removed by just washing down the
board with water. It is better to use distilled deionized water, but I have
found that most warm tap water is pretty effective as well. When I have to
clean a large batch of boards, I throw them into a dishwasher (with the
food trap cleaned and no detergent!). After the boards are washed, set them