To unban a 360, you have to patch the nand with the keyvault of another, unbanned xbox (easier said than done!)
Nand: 16.5mb of code containing the dash
Keyvault: Normally called kv.bin, 16.gmb of code containing the important info about your console (region, DVD key etc)
CPU key: a unique key to each console, without which very little is possible.
How do I extract the keyvault?
Use Robinsod's "Flashtool"
How do I obtain the CPU key?
You must run be running either 4532 or 4548 kernels, and then follow this tutorial: http://gueux-forum.net/index.php?showtopic=166901
How do I get my 360 on 4532/4548?
Either upgrade (use the appropriate update)
or downgrade with the timing attack.
On BOTH consoles:
Get them onto 4532/4548
Dump nand + CPU key
On UNBANNED console:
You must obtain the kv.bin from the unbanned console to inject into the nand of the console you wish to unban. You'll need flashtool.
1) Start flashtool
2) Click "keys" and copy/paste in your 1bl key and the CPU key of the *unbanned* console
3) Click 'Dump Files' and select the nand from the *unbanned* console
4) Click extract, select the box 'Key Vault', click OK and select the place where you wish to put your kv.bin.
Voila, kv.bin has been extracted!
To unban the banned console!
You simply have to patch the banned console's nand with the kv.bin you've just extracted.
1) Run Flashtool
2) Click Keys and copy paste your CPU/1BL keys from your *banned* console, then click OK
3) Click 'Dump Files' and select the nand of the *banned* console.
4) Click 'Patch' then 'Patch Keyvault', then 'Import Keyvault'
5) In the window that's just opened, select the kv.bin you just extracted and select Ok. A second window will open asking you where you wish to save your patched nand. Call it 'deban'.bin and select 'save'.
Congratulations, you have patched your banned xbox's nand with the keyvault from the unbanned console, and it's called 'deban.bin'. Now you need only flash it onto your banned console:
1) Disconnect your console from your screen, disconnect the power cable, and wait 10 second, then reconnect it.
2) Launch the 'Infectus Programmer'. In the red rectangle appears '
?' and the word 'Disconnect' is shown.
3) Connect the USB cable from your PC to the Infectus, and the '
?' will be replaced by figures (in this case, AD73), and 'disconnect' will be replaced by the name of the nand, here 'HY27US08281A'
4) [[Here the instructions say 'return your chip to 0'. I don't understand this; does it make sense to those with infectus?]]. Select 'Flash Command' then 'Erase'. This will take a minute or so.
5) Select 'Flash Command' then 'Blank Check'. This will take around 4 minutes.
6) Select 'Flash Command' then 'Write'. Select 'deban.bin' then 'Open'. This flash will take about 3 minutes.
7) Disconnect your infectus, close the programmer, reconnect your console to your screen, disconnect your power cable, wait 10 seconds, then reconnect it.
Now, go test you have a working, unbanned connection to xbox live!
Note: You don't need the entire keyvault to unban a console, but merely the part from 0x148 to 0xC71 from kv.bin. So if you wish, you could just change this part with a hex editor to unban a console.