Now that we have a finished PCB assembly, it's time to test it. For these tests, you will need a relatively strong magnet and two AA batteries. A magnet salvaged from a car speaker or a rare earth one from a local hobby supplier should work fine. It needs to be fairly strong, so a fridge magnet probably won't work. You are about to find out if your magnet must be big enough by following the given steps:
Make sure you have the magnet handy and then insert the AA batteries into the holder. There is no polarity protection, so be careful; the buzzer should be squealing at this point.
Stand the PCB assembly on end, with the buzzer at the bottom.
Wave the magnet by the reed switch and the howling will stop. Your alarm is now armed.
If you tilt the PCB assembly left or right, the squeal should start again.
This test should give you some idea of just how sensitive this alarm is!
This is an extremely simple circuit, so there is very little to troubleshoot. If things don't work as I said...
