Scantronic 9884 tripping in power cuts

[manbackh]

Hi, having a problem with a 9884 alarm system, wondering if someone can help me.

When we moved in the alarm kept going off when the power was disconnected (which was a lot because electrical work was being done). The box itself was unpowered as well. I replaced the battery in the box but that didn't solve it. An alarm guy came out and replaced the fuse in the box, and that solved the unpowered issue. That was a few months ago. Power has just gone off again and alarm is tripping again. Box is still powered, but entering the code didn't make any difference, alarm rang until it turned off after 10 minutes.

Any suggestions what is going on?

 

[Hoover]

did the alarm trip straight after the power cut or was there a delay?

 

[EightyTwo]

That'll be a 9448 alarm..?

It sounds like the battery or AUX fuse has blown again. Probably the former. You may well have an intermittant fault. The fuse holders on the 9448 are "built to a price" and, if they're not gripping the fuse very well, they can get hot enough to desolder themselves!

Another possible cause is the battery cable connector on the pcb. It is not unknown for the battery to fall out of the panel when it is opened. The battery is quite heavy and this jerks the connector quite hard. This can, in turn, crack the solder joint on the back of the pins. This is called a 'dry joint' and you need to look very carefully to spot them - a thin black line in the solder pad going right round the pin.

You're probably going to have to get your multimeter out (or someone who's got one) before you can get to the bottom of this.

 

[manbackh]

Thanks for advice guys. Answer to first question - it comes on straight away.

Sounds like the problem is beyond my pay grade, guess I'll be getting a pro out.

 

[Hoover]

You need to have a look and a test or get someone to do it for you.

EightyTwo has given you plenty of things to check over.