Xbox 360 Jasper RGH3

2022-07-14

I'd been enjoying my modded OG Xbox when I lucked into getting a Jasper Xbox 360 from a friend who no longer had any use for it that was in quite good condition. Having never experienced a modded Xbox 360 before, I decided to try the recently released RGH3 reset glitch hack for the console so I could use it as a lighter, newer, sleeker alternative to my OG Xbox when traveling or moving about.

RGH3 for a Jasper requires only two conductors, a diode, and resistor and a board of one's choice to flash the console's NAND; I chose the Pi Pico since it was cheap and I could reuse it for other projects. So with the console disassembled, I set to work wiring things up.

The SMC points were wired up with 28AWG wire and a 1n4148 diode with the cathode end pointing to the POST point (towards the front of the console). This would not prove troublesome, though I did wrap this wire in some grounded 34AWG magnet wire later for precautionary shielding.

For the 22k ohm resistor recommended for most Jasper's, I wired 4 5.5k ohm resistors in series (the yellow package). Here I made a mistake that proved troublesome, using unshielded 34AWG magnet wire for the PLL wiring as well as using the topside PLL point, a longer route. With the precision required by RGH, I'm not surprised that these mistakes caused freezing and instability after I buttoned the console back up, rendering gameplay impossible. This, of course, was rectified later, but is documented here as reminder to always use proper gauge and shorter routes.

After everything was soldered up, I read the NAND (twice) using JRunner with Extras, created and wrote the new glitched ECC, and then created and flashed the new XeBuild image.

Ah, success! The console booted into Xell successfully after a brief scare before realizing my power strip wasn't turned on.

Like I said previously, I ran into freezing and instability after the first go at the mod, so I went back and redid all the wiring. With 28AWG and shorter routes, along with some shielding, everything after that played just fine.

I'm quite happy with how this turned out and believe I'll get a lot of utility out of having an RGH3 Xbox 360. Unlike the OG Xbox, transferring files via USB is much more feasible for quick tests without firing up an FTP transfer, enabling me to test OG Xbox game mods and homebrew a lot more quickly. This will render it a quite nice development box.

And, as an entertainment machine, it's still an Xbox 360, so with hacked back-compat files, I have access to a plethora of great Xbox and Xbox 360 games that I can enjoy comfortably with wireless controllers and HD visuals. Now I won't have to lug the entire OG Xbox setup around to other folk's houses!