Xbox Doc

Here are some of my notes on the original xbox's hardware, without any warranty of correctness. I took this readings on a revision v1.4 xbox.

Voltages

You will find many of the main voltage lines in the "compendium". [GIMP project file]

12V

Mostly for the HDD & DVD-ROM. Also used for the regulated fan voltage. IDK what else is using it [about 100mA], but it's required for booting. Regulated by the PSU.

9V

IDK what this is used for, it's in the A/V-Section of the Mainboard so it might be for some component there. No boot requirement.

5V

Is feeding two 1v7 requlators and the HDD, drawing about 13A! This is one of the reasons why you can't portablize it. Regulated by the PSU.

3v3

Is feeding the 2v65 regulator. Common voltage for a lot of components. Regulated by the PSU.

2v65

Draws about 2.5A and is feeding the 1v3 regulator.

1v7

There are two 1v7 requlators on the mainboard. Drawing 5A [CPU] & 8A [GPU?] @5V.

1v3

Draws less them 500mA?! and is used by the RAM.