I had the same problem as you had: after a flash with the wrong firmware the player would not turn on at all.
You can try the enclosed firmware update program "Product Tool No Dog 3.2.0.5" enclosed in this file:
http://www.oem-drivers.com/wp-conten...ct%20tools.rar
This program successfully flashed my RK2698C chip. Also a firmware is included (.rfw) in the download.