Agreeing to and adding this - there is a black fat chip on a socket with a triangle pointing up. This also determines Printer/Modem set up. Most of the time you can work it without touching this jumper block. That is what it is, a jumper block. But if all settings you try does not work, then it's time to switch the jumper block - just carefully remove it, turn it around so the triangle is pointing down , line up the pins with the holes in the socket and put it in. The settings with this block is:

Triangle Up - Printer

Triangle Down - Modem

Good luck to you.