sixwheeledbeast

For Global tamper you have to break them open to measure and compare to as fitted readings for each pair.... It's a Premier so you could go wire them all FSL/EOL then you can narrow the fault down. It may even fix it if one of the tamper pairs are faulty. Yes you can double check by opening it but that is the Aux Tamper. 10 PIR's on 8 zones is asking for trouble.

What's wired into the AUX Tamper?

I took "home office" as Home Office or a government building. You get what you pay for at the end of the day. If the agreement is to use existing infra, even if you don't recommend it and you have that in writing; that's up to them.

Separate network and unmanaged switches. Consider fibre for backbone. You're removing variables that way. Sharing the sites network will only mean liaising with IT departments and intermittent issues you have no control over. Fine, if your site IT on a job creation scheme not so good for us.

I'd say your either following the defaulting instructions incorrectly or very slim chance the panel is duff. We don't provide defaulting instructions here.

Agreed. Control panel being inaccessible and unserviced is most likely the issue. That's if the system hasn't blown something in the meantime.

BUS detection devices would only be compatible with certain compatible control units and there matching manufacturer. Most modern equipment utilises some data BUS type wiring for the keypads and zone expanders, which I believe is the case for the iON. Essentially each device has an address so they can be identified back at the control and they all communicate and get powered from the same line. Often this is wired as a pair for power and pair for data.

Xenon strobes have ~3Kv driver circuit. 230Vac (mains voltages) while dangerous is considered LV (low voltage) in the grand scheme of things.

The strobe would usually be very high voltage unless it's an LED one...

I would use the existing wiring as a base for a hybrid system myself. Too many times have I seen old systems ripped out and junk replacing it. Yes some of the tatty wiring maybe removed but if the system was in good order at some point it may reduce installation or service costs to reuse some of it. For the more direct questions, yes the alarm is likely to sound if you tamper with it. There is no guarantee that any service/engineer modes would work so expect it to rattle your ears. They're designed to be hard to disable and bring attention to the fact someone is tampering with it, if installed and serviced correctly.

Blown fuse or possibly panel. Check for AUX voltage with a multimeter.

Verisure, Eufy, Ring all junk. Texecom is what I fit but not supported for end user installation. Maybe Scantronic?

Hopefully you have the Y splitter cable that comes with the siren or you can't plug them in.

poor security 1 way wireless, discontinued kit, not the most popular model of this old stuff either so not advised for fitting in 2026 at all... MCS-740 is updated model of the 730. Red cap on the lid screw would be a K-305177

Outdoor ones are at least triple the cost? I have put internal equipment (AP) outside in an IP box at customers request, it lasted couple of years before it lost it's marbles. I'd suggest that's a lot of equipment to go down if you have a failure and consider a redesign or using the proper stuff.