gardtec 300 power supply?

Had this alarm for about 15 years only problem ever was to replace back up battery.We had a power cut for 16hours 2 weeks ago, it has been fine since then. But on Friday the power was off for 4hours again for maintenance work on the supply I went to work didnt set the system because I knew there would be no power for part of the day.When I got home power was on but the green power light on the control box was off. Then Saturday mid-morning it went off internally and we couldn't reset it Then in the afternoon all the lights were flashing and it wouldn't do anything at all.Eventually the lights faded an nothing worked box or sensors. At 2.30a.m. the alarm went off outside we took the fuse out o silence it. What do we do now?