In this category are all the interface cards for your printers. Often, the interface cards are the first to be affected in case of overvoltage (lightning for example). They change very easily, just keep them 2 screws. Failure, replacing this card very often allows to avoid having to change thereceipt printer complete.
On the other hand, if you change the software and that theinterface is no longer the right one, you can easily replace it you even.