Hi @vena67 ,
Have you tried a different cord at all? You haven't said.
Try using the player for a while to run down the battery at bit. (Do not let it go past 50%, down to 80% is good enough).
Then turn off the player and plug in the USB cord to the player and connect it to a working PC and see if the player starts to charge. Leave the player switched off when you do this.
If it charges it shows that at least 2 wires in the cord are OK and that the charging circuit works.
When it's finished charging, disconnect the cord and then use a strong light and a magnifying glass to visually inspect the player's USB socket. Ensure that all the pins are still there (there are 5) and that they are all straight and parallel with each other. Also check that there is no dust or lint in the USB socket. If there is use a vacuum cleaner to remove it. Do NOT use a metal probe to try and extract it, you can cause damage by doing this. If vacuuming doesn't work then use a wooden toothpick to very gently remove the lint etc.
If the socket enclosure appear to be OK it may be that one of the two or both of the signalling wires in the socket (the two middle wires pins 2 & 3) have become disconnected from the systemboard in the player. As most likely it is a SMD (Surface Mounted Device) type USB connector you will need the requisite tools and expertise to solder it back on.
If this sounds too daunting I suggest that you contact either a reputable, professional electronics repair service, mobile phone repair service or laptop computer repair service and ask for a quote to repair the player.mobile