Hi Tibor
Seems the device is non-functional and unrecoverable in the field.
That leaves us little choice but to ask that you send the device into
MultiTech for warrantee repair (or replacement).
MultiTech Systems Inc.
2205 Woodale Dr.
Mounds View, MN. 55112
attn: Service
If the device worked for you previously, could you provide more detail around
“appended two lines to /etc/network to start custom services”
-Best Regards