WIFI suddenly stopped working (no hits, no water...)

Hello,

I have a problem with my iPod 1st Generation WIFI (serial N. 9E92109L14P / model MA627ZD).

It doesn't had any hit or water damage...but one day WIFI stopped working.

When I go to Settings/General it is possible to turn on the WIFI switch, but it is unable to find any WIFI net even if it is just over the router (and it works fine with all my other gadgets).

I tried to upgrade and downgrade its firmware, from 3.1.3 (which is instale now) to 2.1 or even 4...but it is still not working.

Do you have an idea about what can be wrong??

Thanks in advance for your help and best regards from Spain!

Cesar