NSA320 back to stock configuration (no replies)

Hello guys,

I'm trying to get back my NSA320 to it original firmware because I want to sell it. I don't remember exactly which configuration I made because was a while ago. I get back the original kernel from upgrade firmware file but it get frozen after:

Starting kernel ...

Uncompressing Linux............................................................................................................................................................................................................................................................................... done, booting the kernel.

Similar to this post: http://forum.doozan.com/read.php?3,8716

Any idea how I have to procede to fix this?

Thanks in advance.