One of the most frequently neglected parts of a system tends to be the power supply—at least when everything is working. Only when things get weird does the power supply begin to get some scrutiny.
The Raspberry Pi owner needs to give the power supply extra respect. Unlike many AVR class boards, where the raw input voltage is followed by an onboard 5 V regulator, the Pi expects its power to be regulated at the input. The Pi does include onboard regulators, but these regulate to lower voltages (3.3 V and lower).
Figure 4-1 illustrates the rather fragile Micro-USB power input connector. There is a large round capacitor directly ...