PeterJames

The red light is normal the tamper light could be anything, every circuit has a 24hr alarm circuit called tamper, if someone tampers with the alarm while its unset the alarm activates to warn the owner that someone is tampering with it. Putting the wrong code in the alarm several times could also cause tamper. As SWB says its difficult to tell you what the cause or fix is without more info and knowing your technical ability we are alarm monkeys not magicians

I stand corrected the GD520 has 16 onboard zones its the old Gal Microtec the only has rio inputs. Its still looking for eols though and have you correctly set the keypad id

As I remember there are no zones on a 520 only outputs. and theyre all looking for eol not shorts

We have a used A3 Lexmark for printing plans I picked up for £40.00 on marketplace

Brother here, I decided my printer hunt by looking at the copy consumables. Which are much cheaper than the originals, and seem to be better in many ways too. Many printer manufacturers have cottoned on that their consumables are copied and they have tried to make it harder each time they produce a new model. Now Im not saying that the latest Brother printers have not done this, Im just saying if you want to keep your consumable costs down its a sensible thing to checkout.

the problem with an app is you have to unlock phone open the app press the button its a bit of a kerfuffle

Looks like there are two receivers FAAC one and the Nice onboard one. The Nice ones are rolling code so have to be programmed to the controller which means an engineer has to attend site plug in a keypad and program them. Not sure about the FAAC receiver could be rolling code or a standard receiver. The Nice rolling code fobs are not cheap but they are more secure than a standard fob as they are not easily cloned.

I didnt know that. Still tat though Oh dear, the internet is an oracle of knowledge but sometimes the internet takes people down a path that leads to a much bigger problem than the original. Do someone a favour and go back to wherever it was that advised you to default the user and installer codes and let people know it may not work out as desired, it may just stop someone else having the same problem as you now find yourself in. If the default installer code is not working its probably a different ADT own default installer code, all you can do now is call ADT and take out a contract, or swap it for something that you have control over.

It was expensive but it was always one way wireless tat. If you have defaulted the panel completely (and it sounds like you have) then the factory engineer code will work. You just need to reprogram it now.

QFA most decent panels come with an app now so you have complete control, arm/disarm omit faulty zones and arm. The service isnt free but probably cheaper than a PAYG SIM and it would have to go through an installer. If your GSM dialler has an output you could wire the output through the sounder circuit, but you would need to understand at least the basics to do it, the fact that you have asked the question makes me think you wont be able to DIY this

Not with three wires though

If you only had three wires coming from your panel 12vdc and trigger how did the SD1 switch off the external sounder? IIRC the SD1 just stopped calling you when you pressed 8. I dont think it rearmed your alarm, and I dont think that the 800L had an input that allowed you to rearm or disable the sounder

Probably is the detector, however, Id still be checking what voltage you have at the detector, if the battery was not replaced before it failed it could have damaged the charging circuit. Especially if the panel is as old as the detector.

What voltage have you got on the 12v aux? When was the last time it was serviced? when was the battery last changed. If the battery is pulling the voltage down this could be causing not enough voltage reaching the detector which could be your problem

Yes thats called back focusing