vietslayer, These players are mass produced in China generally without a brand name. As you may have guessed your player is not really SONY brand Although these players are called M4 Players they do not actually play the MP4 video format. Everything has to be converted to AMV video.
Your firmware is version 9.0.48 which is one of the newer versions so your player is running an ATJ2091, ATJ2097 or CTW500 chipset. At the moment there is no way to repair these players if you have firmware problems so do not try to upgrade your firmware.
Looking at the picture of your player it apears to have a 1.5 inch screen so you will need MP3 Player Utilities 3.68 to convert your videos to AMV.
You can download a copy here:
http://www.mympxplayer.org/amv-conve...ads-df327.html