Another one of life's mysteries, and we shall probably never know
OH WAIT! Silly me! I forgot you can go to ASUS SUPPORT, and download the USER MANUAL,http://www.asus.com/Motherboard/M4N68TMhttp://www.asus.com/Motherboard/M4N68TM#support
Click on the Download tab.
(Knowledge Base / Download / Memory/Device Support / etc)
To the right of the - Select OS - box, click on the blue Down Arrow
Click on WinXP. Doesn't matter what Operating System you choose, you are just going for the User Manual. (Motherboard manual)
Give it a few seconds to load.
Scroll down, click on the + sign to the left of - Manual (5)
Version E5215 M4N68T-M user's manual - English
Click on the blue - Global
A small window will come up -
Make sure the small circle to the left of - Save File, has a Green dot in it.
IF not; left-click in the small circle to the left of - Save File.
Now click on OK below.
A small download window will come up. Allow the file to Fully download, then DOUBLE-click right on the file name.
In the next window go to the left, and click on - Extract all files
At the bottom of the next 3 small windows, click on -
Next, Next, and Finish.
In the last window DOUBLE-click on the file name.
E5215_M4N68T-M to the right of the red Adobe PDF icon.
The front of your computer is the Front Panel.
The area of contact pins on the motherboard, that the main wires go to, is the Front Panel header.
You need a Front Panel header pinout.
When I refer to a page in the manual, it will be for the Adobe Reader page number box, at the top.
Go to Page 1-7
1.5.3 Motherboard layout
Number 12 shows us the Front Panel header.
Motherboard mounted in computer case, the Front Panel header is the 3rd header from the Left; on the bottom of the motherboard.
(System panel connector (10-1 pin F_PANEL)
Go to Page 1-25
System panel connector (10-1 pin F_PANEL)
There are two rows of pins.
4 pins across the Top row; 5 pins across the Bottom row.
Not numbered, so I will;
Starting on the LEFT side, going across to the Right; Top row,
Pins 2, 4, 6, and 8. There is NO Pin 10
Starting on the Left side, going across to the Right; Bottom row,
Pins 1, 3, 5, 7, and 9.
A) Pins 2 and 4 are for the Power On LED. (Light Emitting Diode)
Pin 2 is for the Positive ( + ) wire.
If the PWR LED is dim when the computer is on, switch the wires around.
B) Pins 6 and 8 are for the Power On switch.
C) There is NO Pin 10.
D) Pins 1 and 3 are for the HarDDrive activity LED.
Pin 1 is for the Positive ( + ) wire.
If the HDD LED is dim when the Harddrive is active, switch the wires around.
E) Pins 5 and 7 are for a Reset switch, IF a Reset switch is used.
F) Pin 9 is N/C.
Probably a 5 Volt (DC) point for the factory to test with.
(So it's Reserved for the factory)
Here is an example of an ATX power on switch, that is used in MANY desktop computers,http://www.directron.com/atxswitch.html
Remember; the Power On switch is a Momentary Contact Switch.
This means the contact period you make across those two pins, shouldn't be more than 2 seconds.
Next time you do not know the Front Panel header pinout, of a motherboard;
Use an LED light with two wires.
Touch two pins at a time, going along the FP header.
Computer turns on? You have the Power On switch pins. Now you can continue on.
LED light stays on? You have the Power On LED pins.
LED light blinks? You have the HarDDrive activity LED pins.
Computer restarts? You have the Reset switch pins.
Power On LED winks at you seductively?
Put that left-handed cigarette down, and go get sum fresh air.
For additional questions please post in a Comment.