2007 radio problem

I have just bought a 2007 l322. The radio doesnt come on. Stays on the land rover screen. So, after a search I checked the bluetooth receiver in the boot which seems a prime candidate. There did appear to be some corrosion on the pins and the plug going to them. However, the optic cable that lights up had already been looped back. The light on the power button flashes continuously with the key in. I would have changed it for an aftermarket system but the conversion kits are a tad expensive. Is there a diagnostic function that would diagnose the fault? My basic scanner has no detail. At this point I do not know if the bluetooth unit is faulty or if the wiring loom plug would still stop the radio working when the optic is looped back. Who would be so stupid as to design a system that ****s down all functions for radio sat nav etc as a result of a fault on one element. Any ideas gratefully received.