Fruit Machine Chat

This will sound odd but im wanting to turn off all alarms on my QPS Bell fruits machine, now and then for various reasons i get the tamper alarm goin off and its driving me nuts, i have read the manual and it simply says turn dip switch 13 on, which i have done, u would think that would be it sorted but nope still the alarm sounds, any advice?? am i missing something :

You should try and avoid tooling it i reckon