Russ's story shows you don't need the latest test hi tech weapons in your arsenal or even massive know how, the sheer value of common sense and using observation are all very powerful tools.
where i used to work for, a system in London kept falseing on 2 pir's, several new units fitted, lots of discussion and head scratching then panel changed, then 2 x supervisors another pir change, then manager, more head scratching. i offer several times - but get 'your only the new guy' (like i'm some sort of novice
finally the service controller is so fed up with the client's by now regular abuse, in desperation he decides to take matters into his own hands say's (F'@) the supervisors and send's me as a last ditch attempt. obviously, i'm right on my metal i have to get a result or be deemed just another 'wally'. so i started out afresh and decided to inspect inch by inch the whole cable run real close up, i expected to find rodent damage, boy did it wiggle about the building but no damage. finally found it went through the wash rooms, in there was one of those big M/F gas boiler/geyser's size of a an apollo rocket motor, the wire i discover was buried under aertex and had been run behind it, and sspotted it likely lightly squashed by the hot water outlet pipe, run up the boiler and bingo got the short.
that wire must have been there for years, and obviously not replaced in the update by the instal engineer, over time due to heat and vibration it got rubbed through. if the geyser was run for an extended time it shorted on the core's, and it served a flat as well as the tobacconists shop. if they run the bath for instance the pipe expanded and caused a short of went the alarm. by the time our guys got there it had obviously cooled and so removed the short - the sub never mentioned the coincidence to anyone. the heat from the pipe dried out any damp in the wall, so no earth gave away any clue and so be traced.
the alarm i found out from the client during my usual gentle interegation disguised as chat, had been upgraded due to false alarms about a year previous, it had been all quiet for 6 months through summer and started playing up. now by luck, chance, intuition whatever i get it on the first 'pop' and within an hour of walking through the door and proved the fault conclusively - yes me the 'new guy'.
i'm not claiming to be 'special' but have a very pedantice way about me and the way i do things, and really i admit i just got 'lucky'. but how embarresing was that for the supervisors and manager, and did the service controller and i revel in it - ooooh deeeeaar!. you just bet yourself we did at every chance
probalby why i never made 'super'