I went through so many Sony Walkmans because of loose connections in the headphone jack. You can probably take it apart and figure out what parts are not touching and solder something or the other.
This brings back memories when i used to make recordings of my cd's onto tapes to play on my walkman. Back in the day, you had to have a high end home CD player and Tape Deck with level calibration, azimuth control and all the Dolby B,C and the other one i forget,,. and use overpriced Metal tapes to get good quality recordings. The sound was almost as good CD. It's actually remarkable. The Nakamichi Decks had 3 heads so you could listen to what you just recorded instantly (switching from source to record mode and fiddle with the azimuth and dolby setting on the fly). I'm beginning to show my age... i will now be quiet !