There should not be any response! This will just act as "batt flip out - batt flop in". -- no need to press that long (8-10s is definitely enough) Now after doing so, what does the N9 react like when connecting via USB? What does the PC do (flasher tool, installing drivers)? What kind of USB (mainboard connected, not device front?)? Which PC, which OS (32/64) and so on? Correct flasher version? --what is the behaviour of LED when switching on (power button 3s) after decoupling?