Don't disassemble it, there's nothing interesting inside. The whole problem lies in the ATJxxxx chip itself, and it can't really be fixed.
You should try "Operation Big Freeze". Put the player in the freezer for a night (beware, put it onto plastic or paper first so it doesn't stick to your freezer) and if possible crank up the cold. Then move it to the refrigerator for a few hours.
When taking it out, immediately wrap it into a thick cloth and throw it in the coldest corner of your house so it warms up as slowly as possible, this is the key to succeding.
After another few hours when you're sure your player has reached room temp, take it out of the cloth and enjoy.
90% of the static should be gone now, even static produced while watching video.
It may sound crazy but it did work on my unit. if you search around the forum you will find the guy who proposed this, and some of his even weirder methods of improving sound on these players.
Good luck! 8)