Help! I dont understand the audio connection on my mobo



I am trying to set up the front panel audio/mic cables but have a problem;

Well i dont understand; on my mobo manual it just says BLINE_IN_L and BLINE OUT_R, no line in_r or line_in_l like in my case manual. Then in my mobo book I have 1 more connector than I have in the actual audio wiring. What means what??

What does AGND mean when you look at my case wiring page? Why is there MIC2 and not just plain MIC/MIC_IN like on my case? And what does the +5VA mean?? Ground?

PLEASE help me :sad: Its taken me 45 mins just to get the wiring for the front panel firewire jack sorted because I hadnt done it before putting the mobo in and didnt want to have unscrew the board again and the whole story.

Here is the page from my mobo manual;

and here is the page from my case booklet;

*the pictures are BIG so the writing can be read (about 1mb)


EMERGENCY STOP… 5VA might be 5 volt power for something
least find out first


I havent powed up yet or anything. Is there any way you could tell me what to do?? If someone hasnt managed to help me by tomorow when I get my XP O.S I’ll leave those bit off/not connected. any ideas??


I know its not much help, but with mine I just plugged in the USB and called it good :stuck_out_tongue:


try here including links


thanks man :slight_smile: I unscrewed the mobo, took it out the case and then did it. I was getting to the point that I was taping the little connectors together so that they would go in right, lol. I was worried about damaging the board when taking it out. All sorted now. I decided to only use one of the front usb ports. Im not sure if its right though, its completely flat whereas the external one that came on the game port+2 usb ports card thing has a blocky sort of connection, any ideas??


usb all look the same, a firewire is a little more blocky looking



that is what comes from the front panel usb ports, theres 2 of those;

see the blue ports?? those are double the thickness of the black thing for the front usb ports;

see what i mean?


For your front panel audio, this is the map:

BLINE_OUT_L : Return L
Line out_L : EAR L
BLINE_OUT_R : Return R
Line out_R : EAR R
AGND : Ground

Typically, there are two jumpers on the BLINE_OUT_L/Line out_L and BLINE_OUT_R/Line out_R headers so that your rear panel will send audio out. You will need to remove those jumpers. Since your case doesn’t have a connection for +5VA, just leave that alone.

AGND = Analog GrounND

Just plug in the two blue USB blocks into the header block and you should be fine. You can neglect the missing pin on the header block. From your picture of the USB connection, I believe it’s reversed.


got ya now. Blocky on the mobo. Some special asus connector?? I think I got a couple of cables like that I never used. Not 100% sure what they are for.


The blue enclosed header block is for a RS232 port, notice the “COM” silkscreen.


I encountered the same problem one year ago and even started a thread (, but nobody replied :frowning: . So I had to experiment and after an hour-two I found decision in that situation.
I connected MIC IN to MIC2 connector and GND to AGND connector (see pictures in my thread). MICPWR and +5VA left not connected. That’s for microphone.

As for Speaker Port, all appeared even simpler. Two Spkout L go to Line out_L and BLINE_OUT_L, and two Spkout R go to Line out_R and BLINE_OUT_R. In such configuration everything works fine.

Now you have some other schema with line_in_r and line_in_l. A few weeks ago I saw some cheap JNC case with these connectors. And also didn’t know where to connect them – therefore front audio panel left unconnected. And I don’t know the answer till now … :sad:
I don’t understand why they are IN connectors, when the speaker port is OUT-port in its nature…. :confused:

That means that every manufacturer has its special and extraordinary view on standards :doh:


So you mean that the two flat things that are for the front USB ports go flat against eachother in that ONE USB block on the board?


All motherboards use the rear panel audio jacks by default, thus, typically, you’ll see the jumpers at two positions. However, it is an inconvenience to always reach back if you want to plug in a microphone or set of speakers if your computer is stored away. With the front panel connections, whenever speakers and/or microphone are used through them, the rear connections are disabled. However, when no connections are made at the front, there needs to be a way for the audio to travel back to the rear, thus, you see the “IN” pins. The CMOS is smart enough to detect when front connections are made and will have priority all the time.


Yes. :slight_smile:

Just make sure you plug them in correctly. I believe the red (VCC) wire should be closest to the other USB double-row header block.


As I know USB connectors must be connected in following sequence from left to right = red-white-green-black. (as you have those two double-thick connectors connected). So you have to connect two thin connectors (red-white-green-black) to USB 9 10 in the same manner as are connected the thick connectors in the left. Did I understand a problem correctly?


not quite oleh :wink:
like this???:


I believe you still have them reversed. Just flip the two single USB rows to have the red wire closest to the USB block immediate to the left of it. Verify by checking with the manual. I don’t think Asus would reposition one USB header block differently than the other two.


Just had a look, you were right. the ground pins are to the far right. cheers man :slight_smile:

So that means that the front USB ports only get half the speed or is are they full speed?


Yes, but in opposite order - from left to right - red-white-green-black.