SV-1 stop detecting voice URGENT!!!!

Hi! I was using my SV-1 with Superlab and suddenly stopped detecting voice. If I turn threshold to “minus” voice light is still on permanently.
I tried to change microphone and it didn´t work either.
Did it happen to anyone something like this? Can anyone help me?
Thanks a lot.
Natalia

Turning the Threshold dial all the counterclockwise (towards the minus) makes SV-1 quite sensitive and it will pick up the slightest noise. This would make the Voice Key LED light up a lot, though not permanently.

Is the Power LED flashing by any chance? this might indicate a low battery.