Xbox 360:RGH/EXT CLK

The steps on this page are considered risky for your console, as there is a chance you can brick it. Please have someone else mod your console if you are not experienced in soldering!

EXT_CLK is a modern RGH method by Octal450 that uses the EXT_CLK_EN point instead of CPU_PLL_BYPASS to allow reliable glitching of Xenon and Zephyr Xbox 360 consoles.

Equipment Needed

• A compatible glitch chip:
  • Coolrunner Rev A/B/C/D
  • Matrix Glitcher
  • X360ACE V1/V2/V3
  • It is highly recommended to use STBY_CLK instead of a built in oscillator with EXT_CLK, but if you wish to install a crystal on a glitch chip or use a chip's preinstalled crystal it's best to use a 48 MHz one.
• A PC running Windows Vista or later
• A soldering iron, solder, flux, and Isopropyl alcohol with cotton swabs
  • Specific recommendatons can be found on this page
• A NAND & Glitch Chip Programmer:
  • xFlasher 360
  • NAND-X
  • JR-Programmer
  • Modified Matrix Flasher
• J-Runner with Extras (Includes EXT_CLK Matrix/Coolrunner Timings)
• EXT_CLK Timing Files (X360ACE chips only)
• A NAND Backup with XeLL written to the console

Reading your NAND

There are a few different tools for reading your NAND chip: xFlasher 360, Nand-X, JR Programmer, Matrix USB NAND Flasher, PicoFlasher, various SD card tools, or a LPT cable. Consider the pros and cons below and choose the method that’s right for you. The LPT cable method is not recommended, as it's extremely slow, requires more work than other options, and cannot be used to program glitch chips.

Tutorial for backing up and writing XeLL to the NAND

Device	Pros	Cons
xFlasher 360	Reads NAND fast in 40 seconds to 4 minutes Can also program glitch chips One of four options for 4GB Corona Actively supported USB-C Uses signed drivers	Most expensive flasher Can't be used for flashing Sonus Sounds
Nand-X	*Reads NAND fast in 1-8 minutes One of four options for 4GB Corona One of the two options for Sonus or Slim sound programming Super cheap Easy to find Uses signed drivers	Can't easily be used to flash glitch chips
JR Programmer	Reads NAND in 2-8 minutes Can also program RGH glitch chips	More expensive than most NAND flashers Not much cheaper than the xFlasher Does not support 4GB Coronas Requires unsigned drivers
PicoFlasher	Reads NAND in 3-10 minutes Can also program glitch chips One of the two options for Sonus or Slim sound programming Cheap Easy to find	More expensive than PicoFlasher or Matrix Does not support 4GB Coronas Requires unsigned drivers
Matrix USB NAND Flasher	Reads NAND in 7-26 minutes Super cheap	Can’t be used for programming glitch chips unless you modify it Does not support 4GB Coronas Requires unsigned drivers
LPT Cable	Cheap Doesn't require unsigned drivers	Requires PC with a native parallel port and more equipment More difficult Can’t be used for programming glitch chips Takes 30-150 minutes to read NANDs

Glitch Chip Installation

Motherboard points

Phat (Xenon/Non-Xenon)

The points you need to solder to are similar to RGH 1.2, aside from using EXT_CLK instead of PLL.

Glitch Chip Pinouts

Matrix

• A - RST
• B - POST
• C - STBY_CLK (remove oscillator if equipped)
• F - EXT_CLK
  • If you have a Matrix that comes with an oscillator, it can be easily disabled if this resistor is removed instead of removing the entire oscillator.

Coolrunner

• A - EXT_CLK
• B - STBY_CLK (remove oscillator if equipped)
• C - POST
• D - RST

X360ACE (V1/V2/V3), DGX

• C - POST
• D - RST
• F - EXT_CLK (22K ohm resistor required)
• Remember to remove the diode and connect 1.8V

Programming the Glitch Chip

1. Plug the cable from your programmer into the chip programmer.
   • If you are using an xFlasher, ensure the switch is set to SPI.
   • CoolRunner: Slide switch to "PRG".
2. Open J-Runner with Extras. Click "Program Timing File" in the upper left and select your console’s tab and the relevant radio button for EXT_CLK.
   • You can use the timing assistant in the bottom left to auto select a safe timing for your motherboard revision.
3. Click "Program". When complete, unplug the cable from the glitch chip.
   • Coolrunner: Set the switch back to "NOR".

Decrypting the NAND

1. Connect Ethernet and power on the console. The Coolrunner should blink once or more times, and then the console should start into XeLL RELOADED.
2. Once XeLL finishes, it will display your CPU key and some other info. There is also an IP address.
3. Enter the IP address into the box on the lower right of J-Runner and click "Get CPU Key". J-Runner will pull the info from the box, and decrypt the NANDs automatically.

Writing New NAND Image

1. Power down the console, and connect your programmer to the motherboard.
   • If you are using an xFlasher, ensure the switch is set to SPI.
2. In the upper right of J-Runner, ensure the Glitch2 radio button is selected.
   • For Non-Xenon boards, select SMC+
3. Click Create XeBuild Image. This will take a few moments.
4. Click Write NAND.
5. Disconnect your programmer when the process completes.
6. Boot the console several times and ensure it boots consistently. If not, make sure your wiring is clean and neat and avoids noisy area. Run the wires near the X-Clamps for best results.
7. Tune glitch chip timings if necessary.
8. Return to the RGH main page and continue in the Cleaning Up section.

Tuning Boot Times

• If the light stays on at the end of a cycle:
  • This means that the checks were passed, but the console failed to start
  • Probably the timing is too low, or the pulse length is too large

• If the light goes off at the end of a cycle but doesn't boot:
  • This means that the checks failed
  • Probably the timing is too high, or the pulse length is too small

Note: Debug light behavior may be slightly misleading due to using POST_OUT bit 0.