IJE71

My alarm started going off while it was parked in the garage so I went to turn it off using the fob and nothing happened so I opened the door with the key and tried using the keypad. I input the pin but again, nothing. The small LED on the keypad does'nt light up when the keys are pressed and the LED in the centre of the dash has stopped working. Its like the whole system is completely dead. I disconected the battery and the alarm stopped but starts again as soon as I reconnect the battery. I have removed the unit, (Sigma M30) but there is no visable damage on the board, any ideas?