House Alarm, Make OPTIMA XM6?

A few days ago main power supply in the area went off for about 20 minutes. When it came back, the alarm went off. I tried putting the usual 4 digit code, then it stopped but started flashing on the out of the house indicator. I tried pressing all possible buttons on it, but no sucess. Now the outisde flashing has stopped and there are 3 red lights on tamper, attack and power mode and one green light on the day mode. All otherbuttons has no connection if I press them. Could u please help me how to reset it again.?

Thank you in advance.