Scrap the dialler or swap it for GSM or something
What panel are you fitting this to and what dialler are you using
The inforna dialler should mostly work out of the box , when unused fit allot never had to invert anything but can't remember now lol
Battery pack inside panel probably needs doing to , you have to open panel let it hang from a few wires and hope for the best , it's not best of designs
As above groups is way it's done on dimension, I used to use a code and code reversed
Although jw there is a part set on the dimension no? Or I assume he wants and extra part set
You would still expect to pay decent money , rather than using £20 chimes although you might think they do the trick but that would depend on how seriously your taking an intruder alert
Commercial wired systems or via WiFi cost more as they tend to work better and more often
I assume the school has a fire alarm commercial not battery operated smoke detectors for the home? No sarcasm intended
Not really Samsung makes some good items , IP stuff is okish not very friendly when mixing gear and hikvision also has it top end hear that you wouldn't buy
But it is junk what you bought , it was better you bough new , or atleast returned on eBay within time , within 6months of PayPal
Be serious lol