You used to be able to put strimming wire into coin mechs, bent to a certain angle and simulate coins entering, clocking up credits. It's alternative use was on lawnmowers.
I've had a CADD do a strimmer alarm 30 on me. I'd put a new £20 note in not the old 1 so it thought i was trying something dodgy. I've been told the strimmer alarm 30 is because the machine has been switched off and on too quick.
Saw this alaem code after a friend went nuts bunging pound coins in like a madman (it was on a holey moley). He wasn't impressed as he was 50 down at the time and 30 still due for collecting in the machine.
i was £60 involved yesterday on a rocket money and it alarmed and said strim alarm :x :x :x :x . had a word with the gaffer and told him i had put a lot in and would he give me a bell when its fixed. he rang me within an hour cost me a further £20 for a £25 top then a £75 top straight after, had a look round for the gaffer too buy him a pint but could'nt find him. also had strim alarm come up on a jumpin jack cash, the gaffer came over, took one look and told me never too come back again because i'd tampered with it, was a bit pissed off really cause there was also an all fired up and a shark ravin mad in there too :x
If it happens to me, I usually politely say "It happened last week, and your other staff turned in on and off.. seemed to fix it". 99% of the time they will copy. And the problem is solved.
It can also be triggered by the note changer, as i found out the other day. Put a £20 note in which it took. I *think* the machine tried to reject it, so it spat it out again but it got stuck half way so it was half in the machine and half out. No credits were given so i pulled it out and it flashed up "Strim - Fraud Detected" or something like that. I'm assuming it thought i was doing a note version of the traditional strimming of coins on string!