Xbox 360S 4GB Corona
PicoFlasher Issues

September 21, 2022

Microsoft Xbox 360 Corona main board showing the NAND IC.

When I opened my first Corona 360 to upgrade with RGH3 I was pleased to see that a post fix adapter wasn't needed.  It was not smooth sailing however as this particular unit had a 4GB NAND instead of the standard 16MB.

There are several guides online which lay out the soldering points for the 4GB Coronas, so the wiring wasn't a problem, however when I connected the PicoFlasher to read the nand JRunner could not detect the console.

I checked my solder points, reflowed a few just to ensure the connections were solid and I tried again but still no luck.  A little research  suggested that problems with 4GB Coronas and the PicoFlasher are not uncommon.

A few suggestions revolve around changing the connection order for the flasher.  Normally on other units I would wire the flasher, connect standby power and then launch JRunner.  Weekend Modder did some work on the issue and came up with a method that he felt was reliable, and it can be found here.  I tried his suggestions but unfortunately they did not make any difference for me.

There were many people who claimed that using an SD card reader solution instead of the PicoFlasher provided better results.  As I didn't have any of the purpose built readers available I did some searching and found a homebrew project posted by Darash on the se7ensins forum showing a solution which you can find here.

A little bit of 30AWG wire and a micro SD to SD adapter and I was able to put together a reader.  It certainly wasn't the prettiest build, but there was a chance it would work.  I soldered new Dupont wires to the board as there are some differences between those needed for the SD reader and the PicoFlasher.

Xbox 360 Corona main board with jumpered soldered to the NAND read points.

Once I connected the modified reader to the wires and inserted the card into a PC, it was detected by Windows and I was prompted to format the drive.

Microsoft Windows input box requesting a drive format.

It's critical that you do not proceed with the format process or the NAND will be wiped!!!  Within JRunner choose Advanced/Corona 4GB Read/Write.  Then choose Refresh Drive List, which will show the available drives on your system.  Choose the drive related to the homebrew SD reader and click the Read button.

From there forward the process was pretty standard, writing Xell to the chip, retrieving the necessary keys and then creating a patched RGH3 NAND image and uploading it.