Funny but same player from ebay and same problem . The playes freeze on WELCOME screen . I think this player on ANYKA chip and need to find the service codes for recovery . There is one way that the computer recognizes it as USB device . You need to close two pins on memory like this
Перевод контроллера флэш в тестовый режим (замыканием выводов памяти) – Статьи – FlashBoot.ru . I do it but PC recognize this player as unknown USB device