I bought a pre-owned Beosound Ouverture CD player from auction last year. It forgets the stored sound settings. I set the settings, press store, it shows up stored. The next time it powers on it has forgotten some or all sound  settings and it's random in what it forgets. Someone suggested it has an internal battery but nothing came up when I googled that. Obviously it's a pain having to do the settings every time I use it so I would like to sort it if possible. Many thanks in advance for anyone who has the answer.

Pete