Navi200 firmware upgrade failure

I had a powerbreak during firmware upgrad of my Navi200. Now I have no
connection and the status lamp is of (indicating firmware failure?).
The unit was bought from www.pearl.de but they do not respond to my mails
(bad service!!).
The manufacture has an invlid email on their homepage
(http://www.etopnetwork.com.tw/index.htm) and they do not respond to
messeges send via the support page.

Can anyone help me with a procedure to get the firmware back into the box?
Regards
erik