I'm adding an external switch to my hp desktop but i can't find instructions for ASUS mainboard.

[pschlotterback]

wanting to add an external power switch to my hp but can't find instructions for the ASUS mainboard connection. the missing pin is in the middle of the second row instead of the 9th.  can anyone help here are some pics.

[erico]

@pschlotterback 

I would simply use a multimeter with the household power disconnected to find the two pins in the plug  that connect to the original power switch.

It is a simple single-pole single-throw switch.

All this takes is knowledge of how to use a multimeter in resistance mode and basic electrical/electronic component understanding.

@pschlotterback 

I did find an old post, with a solution from an HP Expert @wb2001 , who departed  a few years ago to the HP Forum cloud, that likely holds a portion of the solution you are seeking. He is still helping.

https://h30434.www3.hp.com/t5/Desktop-Hardware-and-Upgrade-Questions/pin-assignment-for-Power-On-off...

You are going to still need a multimeter to verify which pins match the single-pole on/off switch.

You could also remove the switch from the case temporarily to match the colors of the wires and trace them to the pins on the motherboard header.

This is the kind of connector with male/female pins you will need to make the connection to your desired external power on/off switch

DIY hacking is never truly simple unless you have the knowledge required.