I have had another look at the PSU and using a small tooth pick spinning the Fan I could hear it was catching the Outer Casing / Grill only a tiny bit, so I pushed the centre of the FAN assembly with a small amount of force (pushing the fan away from the grill/casing)
The constant clicking noise has now stopped YAY Silence is Golden i have left the RMA Ticket open for now just in case it re-appears..
Thanks guys n gals