Xbox not reading disks

[iwillrace]

i hope there is someone out there that can help me with this problem i am having with an xbox that i chiped with a chamleon chip loaded with the new m7 bios and a exox 3935 dash i did the xbox for a friend and it worked when i finished but after a night with his kids playing it the xbox boots to the standard ms dash and brings up a sceer that says that the disk is dirty or damaged or not a readable disk this error happens with any disk put in a burned game as well as a store bought game or cd i took the chip out and reinstaled it i tried booting with a evox boot disk but nothing works can any one help me on this does anyone have any ideas i am running out of them thanks for the help