my mother has an older model, MW24FM5, purchased Ded. 2002. Still works great but she is 88 and would like to use the closed captioning so she can read the words that are being spoken. I cannot get it to come on, if you push the closed caption button on the remote, caption 1 and cation 2, then text 1 and text 2 appear and then disappear. Can you tell me how to get the captioning to appear and stay on for her. She has lost the owners manual. Thank you.