It probably means 'open'. It's trying to indicate that you didn't close it properly. If you have any questions or concerns, please use the link below to reach us and also you can contact this phone number 877-467-4289 for further assistance.
OP means the CD lid is open. If you are absolutely sure the CD is positioned correctly and the lid is securely closed and you are still getting the OP notice, then there may be an issue with the player.
I doubt it and don't understand why that's an issue. I bought it to listen to CDs and baseball games and other stations with music in kitchen. This is nice but a basic boombox.
Leaving the boom box in would not cause any issues as it has a power button. It does use negligible amount of current for being plugged in, similar to a table lamp which is not switched on but plugged in.
Thank you for letting us know about your inquiry. This Boombox can definitely read audio books as long as the disc is the correct region. As well, is has great audio, comparable to ones even larger that it.