Toilets, Sinks, Showers, Tubs and Disposals - Hot Tub Problem

A friend asked me to look at a jacuzzi that has not worked since he bought the house a couple of years ago. It's a Romanesque Spa with a Master Power System II pump. I checked power to the controller, and it's getting power. The GFCI breaker on the controller trips when tested. But, nothing else works. I checked the jet controllers and the air hoses were disconnected. I connected them but they don't work. Any suggestions as to where to begin tracing the problem(s)?

Is there no one out there who can just get me started? Or, is there another message board you can direct me to to get some help. I did a Google search on the manufacturer and came up empty. I also did a search on the pump - also came up empty. I really would appreciate any advice you can offer. Thanks.