how or what does a fan control pcb do/work on a Stoves gas oven 444445107?

think i have a faulty fan control pcb ( http://www.espares.co.uk/part/cookers-and-hobs/stoves/p/1092/630/0/0/660722/pcb.html ) as fan trys to run but doesn't move,tested on 230v mains and runs fine.my guess is it switches/controls the neutral on the fan??? currently got it working on the switched live terminal rail ( via micro rotary switch on oven/grill knob) is this safe??? is there a way of testing conrol pcb?

thanks for your help...