Since we dont know the history of your C5 and whether or not the control box or pod are fully functional, I'd be tempted to parcel them both up and send them off to Martin for bench testing.
That way you will know for certain what works and what doesnt, and can decide which route you want to take from there.
If the box and pod are fine, then you can start checking other possibiliies for the cause of the non-running , wire breaks etc etc.