Thomson lyra 6675 Flash Mp3 Player 2GB. Somehow unit locked cannot unlock it. Each time started

Question

Somehow unit locked cannot unlock it. Each time started up, the unit displays message locked and then shuts down. Cannot find manual.have same problem as harrys game accept ,my player locked up when I changed a flat battery I took the batery out and reinstalled it now it turns on stays on but dose not play or any thing