I need to add a RS232(Serial Port) connection to my pc, and unfortunately I'm unable to use RS232 to USB adapter, only direct RS232 connection, I have seen this item: https://www.aliexpress.com/item/MYLB-DB9-RS232-to-10-pin-Ribbon-Cable-Connector-Adapter/32735919280.html? and that seems nice, but I have no idea how to connect something like that, I'm pretty sure that it shouldn't be connected through the PSU, as I don't recall seeing anything similar from a PSU, so I assume you need to connect it directly to the motherboard somehow, which I believe is correct, but still, I don't know how to connect it to the motherboard, and if I even can, here are pictures of my motherboard:

enter image description here enter image description here

My motherboard is MSI B75MA-E33, so Im not even sure its the correct place to ask, but hopefully someone can help me here, thanks! :)


According to the manual for this mainboard, located at the manufacturer's web site: MSI Support, this specific board has the correct connector for the cable you've linked in your post.

Page 11 has the layout of the connectors and other features of the board:

mainboard image 01

Page 22 has a closer detail of the connector, along with the confirmation that this is a serial port. Be sure to note the keyed pin, which appears to be missing on the cable you've linked.

mainboard image 02

Typically the number 1 pin corresponds to the dark stripe on the ribbon cable. Some cables will have the socket filled to prevent or reduce the possibility of incorrect connections.

Your top photo shows most of the legend for JCOM1 and the pins to be used. If you experience communications difficulties, ensure in the BIOS that the port is not intentionally disabled.

  • What an amazing answer, thank you so much for that :) I already found the manual before etc, but that was an amazing and very detailed reply, you helped me a lot, thanks! :) – msacco Sep 10 '18 at 12:13

That MYLB DB9 RS232 to 10 pin Ribbon Cable Connector Adapter goes into that JCOM1 pin header in your top picture. You have to make sure that pin 1(of JCOM1) and the red line(of ribbon cable) are on the same side. You may (or may not) need to also enter BIOS to enable COM1 (or Serial) settings, though usually(with any motherboard really) their defaults are already set and COM1 is enabled.

  • ninja'd by fred_dot_u by 25 seconds (and his answer is better :D) – user9808 Sep 9 '18 at 21:20
  • Thank you as well for your reply, you both helped me a lot :) – msacco Sep 10 '18 at 12:14

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