Modding the XBox

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Hacking the Xbox
Having recently bought and modded a XBox with an Xecuter 3CE chip and "Pro" switch bank, I thought it might be handy to share some more detailed photos of the devices and in particular those of the LED combinations with the new Pro switch which clips underneath the device.

If you are confused about all this, then reading "How a Modchip Works" may help. Confused about why this is legal? This article by benjeremy makes things a bit clearer. In fact all of his posts make a lot of things much clearer ;-)

The entire XBox opening and modification procedure is well documented elsewhere so I won't repeat. Just make sure you have Torx-20 and Torx-10 screwdrivers handy. For my version 1.6 Xbox the following sites were helpful:-
Congrats to Team Xecuter - the Xecuter3 CE is a brilliant piece of engineering and great fun to play with!

For clarity some images are reduced in size - click to view them full-size. Often these are 1000px or 1200px wide, this does allow me to show more detail.
Questions, comments, corrections gratefully accepted via the contact form.

09 May 2005: Noisy Fan Fixed! I've managed to quieten the very noisy Xbox fan by slipping in a resistor pack from a Zalman fan. More details below.

Inside the XBox

Below is an open XBox with the motherboard and components clearly visible.
Top center is the fan and below that the large silver heatsink of the CPU. To the right of the CPU is the heatsink of the GPU.

The pale brown/yellow PCB on the right is the power supply. A modified ATX power supply connector leads from there to the XBox motherboard.
To the left of the fan is the video out connector which has two Torx screws to fasten it securely to the motherboard and to the left of that is the Ethernet port. The smaller white socket to the left of the Ethernet is the DVD-ROM audio connector and below that is the EIDE port.

At the bottom of the picture (which is the front of the XBox) you can see a pair of multi-coloured wire bundles on the left and on the right (mostly hidden under the ATX power cable). These are USB ports leading to the 4 controller ports (two pairs).

The brown bundle of wires just underneath the ATX power cables leads to the XBox front panel, these are the cables for power & eject and the varous LEDs.


Here is the motherboard removed from the case. The front of the Xbox is now at the top of the image. Important components and connectors are labelled (click image to obtain a 1200x1030 image).

XBox Identification

The version 1.6 XBox is distinguished by having an Excalibur video chip and Samsung RAM. Here's what they look like.
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XBox Video chip
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XBox Video chip
Video Chip
(says Excalibur on it and
has an XBox logo top right)
RAM Chip (made by Samsung)

Details of the LPC
The LPC (Low Pin Count) port exists to provide a debugging interface to the XBox. Development XBoxes have this part soldered in place while retail units omit it and only have filled (version 1.0) or unfilled (version 1.1+) solder holes.

The LPC header area in my version 1.6 XBox consisted of an array of 2x8 (16 pins) solder holes with pin 1 marked by a square solder pad and a silk-screened arrow.

This is where a 16-pin header can be soldered onto the board. The mod chip or a test device then plugs into the pin header allowing interaction with the XBox via a 4-bit wide bus clocked at 33MHz. During development and for diagnostics, pin 11 (LAD0 aka D0) can be taken low (shorted to 0Volts or Ground) in order to let the XBox accept a BIOS image via the LPC connector.
[Click to enlarge]
XBox Video chip

Since I had an Executer 3CE with the version 1.6 rebuild PCB I was able to follow the instructions on the Ver 1.6 LCP Rebuild PCB article and save myself some tricky soldering points.

The PCB fits around the LPC header pins and around the LAD{0,1,2,3} vias on the XBox motherboard. A good soldering iron (20W - 30W max) with a fine tip (0.5 mm or so) is useful here. I cleaned and re-tinned my tip after each point and only needed one cup of tea :)

The large scale view (1200x960 px) has the various address lines annotated.
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XBox Video chip

More Construction Details
The modified motherboard showing the Xecuter3 mod chip PCB mounted on the LPC header. The red/orange wire at the top is the "Alternate +5V" and leads to the voltage regulator. (This is for version 1.6 XBoxes only). The red wire pair at the bottom is the Reset/Eject cable.
The red, green and gray wires lead to the underside of the motherboard and connect to the HDD, LAN and D0 connector points. In my case they are soldered to the LPC rebuild PCB (see above).
The black bundle of wires goes out to the Xecuter3 Pro switch (see below) & LEDs.
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The motherboard with mod chip and completed wiring.

Strips of insulating tape have been used to stop the wires criss-crossing too wildly ... when operational the blue/red LEDs on the Xecuter3 shine brightly .... nice one guys!
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The motherboard with mod chip and completed wiring.

Detail of the feed from the voltage regulator +5V leg, component part number U6A1. This is quite easy to solder, just don't keep the iron on the regulator leg for more than 5 seconds or so.

The reverse side of the motherboard showing the rebuild PCB soldered to the LPC header pins. The gray D0 line is taken off the rebuild PCB, the green LAN and red HDD wires are taken off vias on the motherboard. Due to the small diameter of the vias I felt this was the trickiest bit of the whole operation. (Sorry about the white patch of reflected flash on the large image!). Again, strips of insulating tape keep these fine wires from being tangled up.
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The motherboard with mod chip and completed wiring.

Finally, once everything was put back together (after checking for bad solder joints, splashed solder and checking the instructions backwards to ensure no steps had been omitted), I was gratified to see that the XBox booted up again! Careful: putting the drive caddies on top of the power-supply shields it (and you) from errant fingers. Please be careful around power-supplies and mains voltage because mains power can KILL !
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The motherboard with mod chip and completed wiring.

Xecuter Pro Switch
Based on Team Xecuters excellent installation instructions below is a similar arrangement of "what to press" and "what you should get" as regards status LEDs when using the Pro style switch which clips underneath the XBox.

The left-most LED with the Xecuter logo shows X3 status (enabled, disabled or operating on backup Flash), then from left-to-right the other LEDs show Flash Write Protect (Enable or Disable) and Bank Select (4 blue LEDs). In the photos below bank 1234 is selected (switches are in ON-ON-Off-Off position).

Credit: The photos on the left-hand side were created by Team Xecuter, those on the right by myself. Any problems with using the former, please drop me a line (capn13 AT capn13 DOT net) !

Once you have fitted the Xecuter 3/3CE mod chip, fitted power, video and one controller (use Port 1) the following button presses will give different results:

Press Power button briefly. Xecuter 3 mod chip boots and FlashBIOS screen shows on TV.
Xecuter LED glows blue.

Press Power button for about one second. Xecuter 3 mod chip is disabled and XBox boots as normal (if untouched this would be to the Microsoft Dashboard).
Xecuter LED glows red.

Press both Power and Eject buttons. Xecuter 3 mod chip boots using backup (256Kb) RAM and FlashBIOS screen shows on TV.
Xecuter LED glows purple.

RAM Banks and the Pro Switch
The Xecuter3 has 2048Kb of available Flash ROM arranged in 8 banks of 256Kb each. Thus the smallest BIOS image will be of no more than 256Kb so that it fits into just one of these 8 banks.
There is also another 256Kb of Flash ROM which holds a backup copy of the FlashBIOS. This is used when booting the XBox with the Power and Reset buttons pressed. As shown above, the X3 logo will glow purple.

You can upgrade the 256K backup ROM but if you mess up, your backup ROM is gone. Your choice (I didn't bother) but if you are so inclined, Quarkey42 includes Backup BIOS Flashing instructions on in the Xecuter X3 BIOS User Guide.

Switch Settings

On the Pro switch, a switch is On and glows blue when depressed.
The two most common settings will be for banks 1234 or 5678 and thus the switches will be set thus:-

Bank Switch 1Switch 2Switch 3Switch 4
1234ON ONOffOff
5678Off ONOffOff

Please see the section X3 External Switch in the Unofficial X3 Guide & FAQ for a list of all switch combinations. This has pictures of the old (original) X3 switch but the nature of the bank selection has not changed.

Pro Switch with Bank 5678 Selected

In the images above the 4 LEDs on the right of the switch were set to select the first 1024Kb of available Flash on the X3.

In the image on the right, banks 5678 have been selected (switches in position Off-ON-Off-Off) and the X3 has been enabled (X3 logo glows blue).
[Click to enlarge]
XBox Video chip
Here's a screenshot (screen-photo?) of FlashBIOS 3.0.3 booting. If you get this, the mod-chip is working fine and your soldering was ok :)

Information on your hardware is shown during BIOS boot and afterwards (CD & DVD).

The 5 options are pretty self-explanatory.

Network flashing allows you to use your browser to upload a BIOS file which typically has a .bin extension and a size of 1024Kb. Choosing Enable Network Flashing will activate the network interface (Ethernet port) so you need to make a network cable to your switch|router|LAN is plugged in (at both ends!).
Important: I had to use IE on a Windows box to upload the BIOS because Firefox and Mozilla under Linux didn't like it. This is mentioned in the Flashbios instructions which are a useful read.

Inside the XBox
I have always found that the Xbox fan is too noisy. Games console or not, if one is watching movies on it the background hum is very irritating. I wanted to replace the fan but found that it has custom-designed mounts for the Xbox chassis.

However it turns out there is enough space between the two caddies and the motherboard to insert a reduction resistor assembly from a Zalman 80mm quiet case fan.

I sourced mine in the UK from QuietPc ; note that the Zalman fan itself is quiet so that can always go into the spares box for another job!
Zalman reduction resistor assembly

Installed Fan detail
In this detail around the Xbox fan, you will note that the fan header is a two-pin affair (black & red wires only) while the resistor assembly carries 3 wires. This is ok, the white one is used for speed sensing which the Xbox ignores (it simply ups the power to the fan to approximate a speed). The resistor assembly can either fit vertically, snugly against the fan or there is enough slack to bend it underneath the caddies when mounted.

Take care not to bend the resistor assembly too often because the resistor legs may come off the body of the resistor.
You may wish to consider wrapping the resistor and its legs in insulating tape if you are worried about the insulation creeping.

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