This motherboard has 2x5pin PS/2 header. Pin pairs seems to be shorted so that it is actually a 5 pin connector. I found out Vcc and GND pins with multimeter and thought DATA and CLK pins are two that has high impedance towards GND.

Connected mouse as follows from top (keyboard conn.) to bottom:
1. CLK or DATA
2. DATA or CLK
3. GND
4. NC
5. Vcc

Connecting this way just makes keyboard go crazy and does not work. Swapping DATA and CLK does not help so there seems to be something or more wrong.

Someone know pinout for this? Probably MSI has other mobos with the same header.