Hi my wife works at a daycare and after going through a storage room found 2 5272av Califone casette player recorders. They looks brand new. The problem is I can't get any sound out of both of them. The volume control is at 10 and the tape is playing. ( tried several tapes) I checked the headphones out on our sterio and they are good.I plugged into the different headphone outputs and still nothing.There is an externel swithch box as well 1214av-py. I used that and turned volume up on that with still no results. I have no manual and maybe I am just missing something. Any help would be appriciated. Thanks Rick