Certainly the PCB would be involved but unfortunately it won't be a plug-in relay issue. All five similar ones cover other aspects of the car. The PCB module necessarily requires a continously live power feed for hazards but you could check fuse 4 (5 amp) which protects the ignition switched feed to module. There are two connectors to module that could be checked as well. If no luck then a close physical examination of PCB tracks may reveal the problem.
