Yep, do what Dan said, Make sure the lithium battery ( looks like a 10cent piece ) is installed and is installed correctly ie: the right way around.
I have just got one of these MPU326 for a Flash and noticed that it would not exit audit mode until the battery was installed.
I would also check the voltages on your power supply too to make sure they are all correct.
You should have a leaflet supplied with the board that gives the procedure for fitting and setting it up. It gives details about what the flashing led's mean as well as other setup things.
