sixwheeledbeast

The potting looks like there is a crack round that varistor looking component, maybe water has got in... I'd still be investigating the Red "fault" light on the supply.

Fuse has blown on the PSU? The back of the keypad is potted from what I remember so you maybe lucky and cleaning it up will work with a new fuse?

Pretty standard yep.

System with linear transformers normally have DC-DC voltage regulation after rectification, AC voltages wouldn't matter unless under the the required DC voltage. 14V is still high. There are plenty of other system check engineers would do on a service over just voltage. Charging current you would check amperage in series with a good battery. Before this test I would discharge the battery by measuring the system current in alarm and standby.

Aux voltage should be around 13.6Vdc. 14 or more is too high it's likely the voltage regulator is failing. They sometimes have adjustment controls to set voltage lower on the 317 but even so I imagine it's tired and can't push enough amperage to fully charge a battery after a power cut. Most ADE stuff this age is like this and should be considered for upgrade. Modern stuff uses switch mode power supplies and while more complex use a lot less energy over there life.

Oh so the PSU is cooked then...

You say it's reliable but I'd be amazed if it actually charges the battery properly.... I'm all for looking after things in good working order but most ADE stuff I come across is no longer FFP.

You could try but there is no guarantee it will work properly. You will also have the issue that a power cut will disable the alarm signalling. Best option is to upgrade the system/signalling to a more modern digital compatible one.

A D B B C T D A S 49

We have no idea what model panel you have but seems like you have a tamper fault which will need diagnosis. Understanding electronics and owning a multimeter would be a starting point, there's live electrics inside the control box.

I don't think much has happened in printer tech within the last 4 years. I've never rated Lexmark. I've still got my Brother colour laser and I still rate them, just like I've had good Kyocera lasers in the past. A lot of people seem to be getting big colour photocopiers for work instead of printers. For inkjet refillable tank types are becoming more popular.

There is some volume adjustment in the Master User menu but it's less flexible than the engineers options.

Not my system of choice but used a good few over the years they're functional. Powermaster is all 2 way, not the same as the discontinued Powermax. I believed ADT had custom firmware after they took on Visonic, so doesn't default to the off the shelf codes. If that's the case looks like you'll need ADT to reinstall everything, expensive mistake following random stuff online... You can enroll/delete keyfobs from the master user menu it's not an engineer/installer only function.

That's fine. Just note that if your using a PAYG SIM you need to make sure it doesn't expire by sending messages regularly. Also you'll have to keep an eye on the signal to make sure the network is still working. Pretty much all mobile providers have set dates to decommission older phone masts, some have started already. You can't rely on your mobile phone signal as a tell, it will likely use 4G assuming your phone is newer than your alarm... Monitoring has the benefit of polling which continuously checks the device can send/receive messages for those times you need it.