Xbox 360:Zero-Fuse Consoles

Zero-fuse consoles (also called "0 fuse" or "0f" consoles) are Xbox 360s that have a CPU that was never attached to a console during the production process. Essentially, they are unsecured CPUs that never had their eFuses burned to lock it down to be a retail console, test kit, or development kit. Many of this CPUs have surfaced over the years, particularly phat model CPUs, and they can be used as a replacement CPU in a retail console.

Since they are essentially a blank slate, you can configure them in multiple ways:

• As a retail console on any dashboard version (e.g. a JTAG-capable dashboard) running stock software by burning eFuses.
• As an Xbox Development Kit (XDK) running stock XDK software by burning eFuses, for game development and debugging. Theoretically, it could also be made into a test kit, demo kit, or reviewer kit; but they are less desirable as they are essentially limited development kits.
• As a retail-like console running DevGL. This is essentially the stock operating system modified to remove security checks, very similar to freeboot — the software that runs on JTAG/RGH consoles. This preserves the eFuses, retaining the zero-fuse status.
• As an XDK-like console running XDKBuild. This is essentially the development operating system modified to remove security checks. This preserves the eFuses, retaining the zero-fuse status.

While zero-fuse consoles behave the same as an official console with the target configuration, they do have one unique feature. Due to the CPU being unsecured, CPU-level debugging is enabled. This is a very low level debugging feature available via the JTAG interface, which is normally turned off even for official XDKs once eFuses are burned.

Pre-Made Images

Any of the following images can be directly flashed onto your zero-fuse console without any modifications. However, if you want the DVD drive to function, you will need to open it in with Extras, input the CPU key that came with it, click Nand > "Patch Keyvault...", and enter the DVD key and model. If you do not know the model number, you can find it listed in XeLL.

XDKBuild

Note that XDKBuild itself cannot play retail game discs, but having the correct DVD key may be useful if you shadowboot into a retail kernel.

• Xdkbuild zero-fuse jasper bb.zip - CPU Key: F37C0CD50B928F4E67614ACD548A4E49

Building a DevGL Image

If you want to run DevGL, you have the option to create a DevGL image using J-Runner with Extras.

1. Obtain SB_priv.bin and place it in \JRunner\xeBuild\common\ (NOT \JRunner\common\):
2. Launch J-Runner. The DEVGL option should now be available on the right-hand side under the XeBuild area. If you load a zero-fuse DevGL NAND, it will now detect it as a DevGL NAND.
3. Check the "0 fuse" box.
4. Build your image as needed and flash it.