I too had this issue and thanks to Mayer and Chris Campbells post went straight to the problem. I looked at the solder points on the under side of the board for the relays. With the naked eye, nothing looked out of the ordinary; however, under a microscope at the office, was able to see the solder was broken in a circular shape at the base of the pin. Again, it wasnt clearly visible even under the scope until you moved the relay on the other side and then you could clearly see the pin coming in and out of contact with the traces. I had my technician remove the old solder and resolder which after reinstallation has completely solved the issue. For those who dont have a technician available to them, any local electronics repair house could do this for you. Good luck.