Hello ,
This looks like issue in either cable or the interfaces. Usually the firewall will try to get the interface up so that the TFTP communication can go through. In your case, since you have tried changing cable and using Laptop aswell, it might indicate a possible hardware issue. What is the status of the interface LEds? if there are other interface cards added on the ISG, try removing them and see if the eth0/0 interface comes up .
Regards
Vatsa