there is only one pcb on these and it is behind the fascia panel.you remove the fascia panel and then remove the pcb .pcbs are about £35 complete.I have had a problem like this on one that would work ok in test mode but not in normal operating mode and it turned out to be a pcb fault.just be aware that faulty components attached to the pcb will also stop it working so may not be a pcb fault!!!
ck
March 2009