Hello greats ones,
I was having the extenal modem and working just fine. Tried to install additional external USB modem at other port (/dev/input/ttyACM0) several times and removed several times.
Now this external modem doesnot work. On activation, some lights blink and the modem doesnot activate. I tried wvdialconf etc., deleting and reinstalling the modem, PC turning off & on (Windows habits) but the same results.