Scantronic 9500?

Hi.

I have just purchased a premises with the above alarm panel. it is branded as a chubb alarm on the cover, basically the panel was off at the consumer unit and when I turn it on it seems to have squares flashing on the lcd and it sounds like the speaker is trying to make an alarm sound but is instead crackling. I have opened it up and the three fuses seem fine and the pcb (no rust)

If anyone can advise me on how to get it running I would be muchly appreciated as google reckons its a reliable panel, thank you.