The ports on my STE went arse up too but not because of the actual ports but rather their controller chip you can find this on the top right hand side of the keyboard PCB I cant remember the number exactlyI think its a 746 Ic but was a 16 pin bugger you should be able to find it an elctronics cataloge also get your self a socket for the chip too this will help you in replacing the chip.#
All you have to do is remove the old chip (use a soldering Iron and solder sucker)
solder in the chip socket in its place slot the new chip in its place (make sure everythings cool though) the slap the case back on the ST rember to keep any screws and those little pads safe use a small tray or a pot to keep them in.
