XboxDiagnosePowerSupply

For Xbox 1.0-1.5

From the section "Diagnosing a Broken Power Supply" on page 74-75 in the book "Hacking the Xbox" by bunnie.

1. Verify that the power outlet is functional by plugging a lamp into the outlet. Use a 100 watt lamp minimum to accurately simulate the load of the Xbox.

2. Visually inspect the power cord for kinks and cuts.

3. Verify that the power cord plug is firmly seated in the Xbox power receptacle, and the Xbox still does not turn on despite these checks.

4. Visually inspect the inside of the Xbox for char marks or ruptured capacitors. If char marks are visible on the motherboard, then you may have to replace the Xbox motherboard (i.e. buy a new Xbox). If there are char marks on the power supply, then most likely the power supply was damaged and you may begin replacing the power supply. Keep in mind that a power supply failure may also damage the motherboard, so there is still a chance that the Xbox will not work after the power supply is replaced.

5. Verify that the main power supply connector is firmly seated, and that the front panel circuit assembly connector is firmly seated.

6. Verify that the 3.3V standby boltage (3.3VSB) is within specification using a voltmeter. Take this measurement when the Xbox is off but still plugged in. Measure 3.3VSB by probing the sixth wire in the power supply connector from the end closest to the front panel, and any of the black wires on the power connector. You can measure power supply voltages by inserting the tips of a voltmeter probe into the free space between the power wires and the power connector. There is a metal collar around the power wires inside the motherboard power connector's body. If the value of 3.3VSB is not between 3.14 to 3.47 volts, then you may need to replace the power supply.

7. Press the power button on the Xbox to turn it "on" (presumably, if the power supply is broken the Xbox won't do much). If the power supply makes noises or if it smokes, unplug the box and proceed with replacing the power supply. If the box seems dead, measure each of the primary voltages coming from the power supply. The yellow wire should have a voltage between 11.4 to 12.6 volts; the read wire should have between 4.8 to 5.25 volts; and the orange wire should have between 3.14 and 3.47 volts. All these voltages are referenced with respect to the black wire. Also, check that the voltage on the Power OK signal (located at pin 12, the pin farthest from front panel) is above 3.1 volts.

For Xbox 1.6

Xbox 1.6 Power Supply Pinouts

Pin     Signal    Color   Notes
---     ------    -----   -----
1       +5VSB     Orange
2       +5VSB     Orange
3       +5VSB     Orange
4       GND       Black
5       GND       Black
6       GND       Black
7       NC
8       NC
9       GND       Black
10      PWR OK    Blue    Labeled:PWRPK, +3.3VSB, +3.3V when power is on
11      PS ON     White   Labeled:DRV_PWR_ENABLE, +3.3V when power is on
12      GND       Black
13      NC
14      NC
15      GND       Black
16      +5V       Red
17      GND       Black
18      +5VSB     Orange
19      GND       Black
20      +12V      Yellow

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This page has been accessed 100 times. This page was last modified 16:54, 13 February 2010.