Those little Servis type modules in built under freezers

Im about to send in one of those little Servis pcb’s to qer – the one with the 3 led’s on the front that just sit there peeping the alarm cos the compressor doesnt run. I have changed loads of these in the past but Connect have really shot the price up on them so decided to let qer do them for me due to cost. Does anybody know where the problem lies with the pcb? I have had a look through the simple pcb repairs thread on here but there isn’t anything about them.
I would be very greatful to know.
Thanks,
Rob.