After some months of playing tracks as stored,the player has decided to only play certain tracks,and the same ones are  getting repeated.This is obviously down to the format used to convert,but I am not savy enough.       I have an idea this question may have been asked before.........Can anyone enlighten me???????????  Most are copies from CD'S ,converted to MP3  with freeware programme.

If tracks used to play fine, but no longer do so, and you have done nothing to the card, it has nothing to do with "the format used to convert".  If I remember right, these radios only play MP3 files or M3U playlists, and if they played once, they should be fine.

 

It could be that the card has become corrupted somehow, or is flakey, or is making poor contact.

 

Try the card in your PC, and see if it works normally there.

 

You could copy all the content of the card onto a new folder on your PC and then reformat the card. Format as FAT32. Copy the files back to the card and see if it's now ok in the radio.

 

If there are MP3 files that play on your PC but not off the SD card when it's in the radio, the most common reason is certain characters in the filename are not supported by all player software. It's to do with 'character sets' like ASCII, UTF8, etc, where not only can you get foreign language characters like accents, and graphical symbols, but also different versions of punctuation like a simple apostrophe!   But I digress - if a track played once, it should play again.