I have an Altera DE2-115 with an RS232 port. I also have a USB-to-RS232 cable with the connector like this. One is male and the other is female, so they should fit just fine. However, I cannot get them to connect physically due to the protruding screws by the sides.

I can physically unscrew the metal bits on the Altera board, and these connectors would then connect just fine. However, is this a good idea? Will it damage the board somehow?


2 Answers 2


Just unscrew the protruding nuts on one side. You'd think there would be a standard, but there only sortof is and it's only sortof followed. This happens occasionally.

Most of the time, unscrewing the nuts, which are usually jack-screws, won't do any harm. I have seen cases where the nuts held the front plate on or even held things together inside. In those cases, try the other connector instead. Even if a connector comes undone, it won't hurt the signals electrically. Worst case, it falls apart and you wrap some electrical tape around the exposed conducting parts.

  • \$\begingroup\$ I was referring to the electrical connection. I don't want to accidentally send voltage to the wrong pins and damaging the port. \$\endgroup\$
    – geft
    Jul 13, 2014 at 11:05
  • 1
    \$\begingroup\$ @geft: The connectors are not symmetrical, so can't be plugged in the wrong way regardless of the case around them. \$\endgroup\$ Jul 13, 2014 at 11:57
  • \$\begingroup\$ One of the reasons RS232 has been sooo popular is that it's hard to damage the electronics. Crossing signals is not going to damage anything in the short term. Consider the output voltage is specified at +/- 5v minimum and +/-25v max from memory. The current is tiny (10mA range). A look at the MAX232 chip spec often used is educational if you want further details (indefinite short tolerated, +/- 30V input tolerated) \$\endgroup\$
    – Spoon
    Mar 3, 2016 at 11:08

Those screws are there just for screwing the plug into place so it doesn't fall out of the socket. You can safely remove them with a (IIRC) 5mm socket or spanner.


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