How can I reset my Accenta G3 house alarm?

After a power supply cut my alarm will not reset.Blue light outside continues to flash.Remote key pad is not lit up as it usually is.No sound when keys are pressed.No system lights on pad showing.Very faint background light visible when looked at in darkness.
Movement detectors in house appear to be working o.k. as the
L.E.D comes on when you cross their path.
Power supply to alarm panel (does not have key pad)appears
o.k. and power appears to be going into the remote key pad.