Dual booting GHR / original is interesting but i didn't want to spend any money on a cygnos rev.E cause HY27US08281A NANDs are widely avaiable on broken XBOXes, so here we go. Follow this simple schematic, you just need an additional HY27US08281A NAND, Mini On-On (2 Way) Switch and 10K ohm resistor (assuming you have already installed a glitchip on your xbox and you have a working SPI programmer):
Locate this zone:
Cut and scratch indicated points:
Solder a wire to the scratched point, obviously to the side of the track that is going to the southbridge, test the cut with multimeter or at least microscope:
Prepare the additional NAND by bending the pins to a nice 90 degrees as seen in this picture, you don't need to flash it before installing because spi programmer will deal with both afterward :
Remember to lift pin 9 (it's the chip enable pin):
You need to solder each "green" pin (see above schematic) from NAND1 to corrisponding one of NAND2, NC pins are not connected so you can short them, cut them, ecc... it doesn' t matter, the final result of the "2 sandwich" NANDs will be similar to this:
Now you can select between the 2 NANDs with the switch (don't do it when the xbox is turned on), so you can flash them just using your SPI Flasher (USB or LPT), cutting GND connection to the "glitchip" will also let the xbox boot normally with the original kernel (just make sure to flash image_00000000.ecc to NAND2 if you followed above schematic)
Segnalibri