Jasper 512MB doesn't boot after Xell

[Vampirtc]

I managed to get three identical NAND dumps. But after writting Xell Xbox 360 simply doesn't respond to on. When I write original nand back it works.
I used multibuilder and +w64 command for ecc.

Any ideas?

 

[ball00]

Coolrunner programmed ok? Wires placed as in tutorials especially blue and yellow? Soldering checked out ok with multimeter? Does the xbox boot with original nand flashed back? Need some more details to troubleshoot properly. Ie what do you mean doesn't respond? No power? Centre light does what?