I did what you told me but didn't work. It detects the usb but don't read it. In the end it shows several messages: something about tftp, and searching some files, like xenon.z
One of those messages says: "MMC Console Detected! Skipping uda0:/updxell.bin" and "MMC Console Detected! Skipping...
As the tittle says, I bricked my xbox 360 trying to update it to 17559
I was following a video to update it.
In the video I used an app called "Simple 360 NAND flasher 1.4b (BETA)", I understand first I did a backup of the nand. With it I got some files, one of them "flashdmp.bin". After that...