On my ASUS A8N-SLI Mother board there are 19 pins of a 20 pin connector and the 10 pin connector shown in the manual is not installed, only soldered through. This makes it a bit uncertain about connection of the pwr reset etc connections that go to this connector. Do you know the correct pin assignments for the 20 position system panel connector?

Here is the manual for your motherboard (since describing a diagram probably isn't very useful...)
http://dlcdnet.asus.com/pub/ASUS/mb/socket939/A8N-SLI/e2024_a8n-sli.pdf

You want to look at pages 27-35, they describe what you need to plug into the motherboard. Basically make sure you have connected:

1) 24-pin power cable (from power supply)
2) 4-pin power cable (for CPU from power supply)
3) Any case fans with 3/4 pin connectors.
3) hard drives (SATA or IDE)
4) USB front panel ports
5) Audio front panel ports
6) Case plugs (power LED, hdd LED, power switch, and reset switch).

Please enter your bios. Open your manual to page 2-28.
Make sure there is a jumper covering pins 5 & 6 & pins 9 & 10. As shown in your manual. Pin 10 is marked, BLINE_OUT_L, pin 9 is marked, Line out_L. This is the default setting sending audio out and in from the rear side of the MB. The reason you received "No Audio Device", is most likely because the AC'97 is not set to [Enabled] within the bios. See page 4-24 in your manual.
Check & adjust these setting while in the bios. Save & exit the bios. Your system will auto restart. Wait for windows to fully load and than check windows for possible updates.

Cheers'
Mike

939 pin Athlon 64 X2 / Athlon 64 FX / Athlon 64 are the supported CPU's.
For the SLI connector, it's a 2 1/2 inch connector. (63.5mm).

Most mother boards have an internal USB connector.
Have a read through *********** board manual it will describe all the connectors. If you don't have the manual you should be able to find it in the ASUS web site.

Also if you look really close at the Mother board and read the little white writing next to the connectors you may spot it.

I just took the lid of my pc to prove it can be done.
Mine is labled USB3 it has a block of 10 pins (male) and one is blank so it is really 9 pins. You mother board will be different to mine but have a look and see what you can find.

the boards today have real fine typeset near the connection pins but they are there

http://support.asus.com/download/download_item.aspx?model=A8N-SLI%20Premium
download from here.

first of all you need to connected the power supply connector, processor connector, hdd connector, cd rom connector.
check it

Hi Chris, the problem can be one of two issues. If the sound jack located at the back of the PC did function at the same time as the front case sound jack. Than the problem is the jack it's self is bad. (Back of PC). Someone had to hook up the front mic & sound jack to the motherboard. So disconnecting the front sound & mic may give you rear sound & mic.
Turn to page 2-29 in you're user manual for the Asus M2N-SLI. The pic shown is the default setting for the front case audio & mic. (What you do see are the two jumpers connected). So disconnect any connector & place a jumper over pins 9 & 10, (last two pins at the right of the two rows of pins). Place another jumper over pins 5 & 6.
Pin 1 is the first pin on the left bottom row (MIC2). Pin 2 is the first pin, left edge top row (AGND). Pin 8 is not installed but you still count its spot as if there was a pin. (This is how the board was setup from factory). Once you fix this you should regain sound & mic function at the rear of the PC. To fine tune the audio run the Asus sound effect manager. If you installed this software, (Recommended). If it’s not by you're clock than it’s in control panel.
Link to all for M2N-E SLI
http://support.asus.com/download/download.aspx?modelname=M2N-E%20SLI&SLanguage=en-us

Good Luck!
m

I went through your bios manual three times & did not come across a setting that gives you the option as you listed above.
What I did come across & triple checked your Manual Pg. 2-28 section 14. Asus EZ selector card connector (144-pin SLI_CON.
When using two PCIE SLI cards make sure the card is seated correctly & set for Dual Video Cards. (extreamly important).
Pg. 4-34, section 4.4.9 SLI mode Recommend kepping to Auto. Than the Bios detects the setting of theSLI selector card.
Refering to the sentance above the manual recommends all settings be set to Auto. Your Bios will do the rest. If for unknown reason you no longer have your manual you can download it from Asus. You'll need to fill in the 3 windows under, Please Select the Product.
Motherboard
Socket939
A8N-SLI Premium
Any more question Drucos, please feel free to post back here!
& please vote...

Sounds like the power supply is overloaded. Is this a new configuration? Start removing components until it powers up. If it still doesn't power up, check to ensure you don't have a short in any of the connectors that you installed components into. Sometimes when a video card, memory DIMM, or whatever, gets installed, there is a chance that a connector pin will get crushed and short out to nearby pins. If none of those work, you might want to try a larger wattage power supply. Good luck.