We just upgraded the firmware of our 7941s. All are good except one. It doesn't upgrade at all. I factory reset it by holding #, 123456789*0#.
After this, it's still not fixed. Then I directly connected it to a laptop as TFTP server with SEPxxxxxx.cnf, term41.defaults.loads, etc. with it.
However the phone is not responding at all. Then I factory reset it again the 2nd time. Now the speaker button & line button blink once, then it's dead. no power.
I also tried connecting a power supply but the same happens. the speaker button & line button blink once, then it's dead.
Can anyone help me how to troubleshoot it? Or the only thing I should do is forward it to TAC?