Onkyo A-RV401 amp is not sending any sound to the...

Question

I have a 12 year old Onkyo amplifier(not used that much) that doesnot send sound to the speakers anymore. The owners manual lists an activated circuit protection as one possibility. Can this circuit protection be reset or does this require replacing some electronic part by a service shop familiar with this product? If so the cost may not be worth it. Need your advice!