Something that I have been wanting to do forever is to hard mod an original Xbox by flashing a custom bios to the system, also called a “TSOP flash“. Where the name TSOP (thin small outline package) refers to the type of IC package used on the original Xbox. Flashing the bios is a fairly straightforward procedure if you know how but if you are starting out fresh it can seem like a daunting task as there is so much information available. Hence I thought it would be a good idea share my experience.
Disabling write protection
The first step to modding any original Xbox is to identify the model or hardware revision of your system. This is an important step as methods differ with between hardware revisions. My system is hardware revision 1.0 and does not have a TSOP made by SHARP. This means that to able to flash the bios points R7D3 (top) and R7R3 (bottom) need to be bridged. I fluxed both points before applying solder to one pad and dragging it to the other, making sure to apply heat to both pads in order for the solder to flow and a bridge to form.
Running unsigned code
As my Xbox was never modded before I had run an exploit in order to run unsigned code (i.e. the XblastOS application). Save game exploits have been available for some time but since the release of the ENDGAME exploit they have become less relevant. I used this version as it comes with all the necessary files included. Following the included instructions I placed the files on a specially prepared USB drive. The exploit is triggered when opening the memory card from the Microsoft dashboard after connecting the USB drive to the Xbox. This can be done with a Xbox to USB cable.
Flashing the BIOS
If the exploit worked the payload will have started and a customized version of UnleashX will show. For my situation I proceeded with the ‘Any’ TSOP option. After some files are installed XblastOS is lauched. Choose HDDFLASH (under settings, Flashmenu) and select the BIOS file. Follow the instructions on screen to start flashing the BIOS.
Maintenance required
During the process I found some capacitors near the CPU that looked like they failed. While they did not prevent the Xbox from working I thought it would be best to replace them with fresh ones. And with the system open I can recommend changing the thermal paste too. After so many years the old thermal paste has dried up and its quite hard to remove. Lastly, my system had its clock capacitor removed previously. It is recommended to remove it from the Xbox as it tends to fail and leak, causing damage to components and the PCB.
