Hi Daniele,
and here is the answer to the 1-million-$-question:
Your Zaurus is OK, the internal charger is fried.
What happened:
Your ac adaptor fried the charger, the battery is not charged
any more.
Without a minimum battery load, the Zaurus will only go into
the diag. So the battery was simply drained while you watched
your photos -> Zaurus off.
A few bad NAND blocks are normal, you'll see them even in
a brand new Zaurus.
Now you have the usual 2 options:
If your dealer sold you that ac adaptor and it's not a original
EA-70, it's a warranty case for you :-)
If you bought the adaptor seperate from the Zaurus, you may
return it to Japan for a normal repair or charge your battery
outside using the CE-BC21 battery charger.
///TRIsoft
Marc Stephan