There seems to be quite a few new rockchip players now being sold, these can be easily modded, but it is very important to safely backup your firmware folders first, these are located in a 60Mb "hidden partition"
Important! This procedure only works for the new Rockchip RK27xx series players.
Using windows explorer copy the rkusb.tag file to the root of the main memory of your mp4 player.
Disconnect and important to shutdown the player completely.
Wait a few seconds.
Reconnect the player to the usb and the player will restart.
Look in windows explorer for a new drive, it is the "hidden firmware partition", it should be only around 60Mb in size with 4 folders in it like this:-
and maybe a settings file called RKFSWFRC.FRC.
It takes quite a while for the firmware partition to appear so be patient.
Make at least 2 copies of all these 4 folders to your computer and keep them safe, burn extra copies to a cd or even better upload them to www.mympxplayer.org
together with a photo of your player and where you got it from.
DO NOT delete any of these folders from the hidden firmware partition OR format the partition UNTIL you have safely made at least 2 backup copies.
Once you have a safe copy of the firmware folders you can remove rkusb.tag from the root of the main memory of the player to close the firmware partition to keep it safe
IF you have an unbranded player it is VERY important NOT to lose ANY of the firmware folders, you may never be able to replace them!
(you can download rkusb.tag from the downloads tools on this site)
To upload your extracted firmware go to this page:-
http://mympx.org/Downloads (you will need to be logged in)
Then click on the link "Click here to submit a File", fill out the details and click the "Submit File" button, and please remember to include a photo of your player.
Some members are reporting that this is not working on their player, I can only guess that the manufacturer is blocking this activity by using an unknown "tag" name, if this is the case there is nothing that can be done to expose the hidden partition, sorry to say.