I have an Onkyo TX-SR505

Question

I have an Onkyo TX-SR505 sound system which runs the sound from the TV through ceiling surround speakers. When I closed the cabinet door recently, I must have hit something and now I cannot get sound except through the Tv itself. I have tried every button combination I could think of and nothing has worked. The company that installed the system seems uninterested in coming back to help. Any ideas?