I have xbox360 slim/trinity and i dumped its 16 mb nand 4 times with nandxv3/nandpro3.0a through Xnand Healer. Problem is have bad block in 0x002->0x3ff Xell region. 360 flash tool or any other tool is unable to read nand or open image. i tried building xell through donor nand but got write Error on block 0x002 while writing ecc file to xbox(same block on which i got error while reading every time) that i made through donor nand, i cant read/write/erase 0x002->0x3ff this block so i cant remap my nand.i tried many times to fix it through "Fix it" button in xnandhealergui but same error while writing. After writing ecc console doesnt boot and gives redlight after 3 or 4 minutes, i wrote back original nand and its booting fine