ok if you have wrote your image to the nand using a nand x your nand is not remapped and zaphers can be a bitch to rgh with a good nand so remake your image with J-Runner i posted the link above for you.
Then when your image is made you will find it in a work folder in J-R then get a formatted USB stick and put the nandflash.bin & the xenon.elf on it then plug it in the console and boot the console using the eject button let it update it will also remap your bad block this way.