# Article: Fix front panel audio EMI noise



## itsakjt (Apr 29, 2014)

I was having a problem with my front panel audio port for a long time until yesterday I found a solution. I am sure many of you have that problem.. So here I start.

*SYMPTOMS*

While listening either through headphones or speakers through the front panel audio, you can hear a whining noise which varies and you can feel the HDD accessing, mouse movements, scrolling etc. The sound might get worse when you access a USB device connected to the front port such as copy files etc.

Here is a video of the problem I was having.

*youtu.be/18i_0eWM1do

*THE CAUSE*

Some cases from reputed brands like Cooler Master, NZXT, Antec etc have the front panel designed such that the front USB and the front audio share a common ground. Here is an example. Image is reference image. May and will differ in your chassis.

*img.techpowerup.org/130716/2013-07-16 20.41.57.jpg

As you can see there, both the USB and the audio share the same ground. Therefore, the motherboard EMI shielding no more works as the sound card receives noise from USB signals.

*THE FIX*

*Things you will need.*

1. Screw drivers
2. Any sharp object(s)
3. Multimeter(you won't need it if you are absolutely confident-You will soon know what I mean)
4. Access to the chassis' front panel PCB
5. Basic circuit understanding skills
6. Last but not the least - PATIENCE.

*Step 1* : Get access to the front panel PCB. Remove the plugs from the motherboard headers and work in a good space.

*Step 2* : Carefully understand the circuits.

Switch the multimeter to diode or resistance mode. Connect the probes as shown and you will get 0 or continuous beep value meaning they are the same or continuous.

*img.techpowerup.org/130716/2013-07-16 20.41.57 (2).jpg

The exact circuit layout is like this in the PCB I am using for reference

*img.techpowerup.org/130716/2013-07-16 20.41.57 (2)752.jpg

*Step 3* : Break the required circuits.

*img.techpowerup.org/130716/2013-07-16 20.41.57 (3).jpg

Take a sharp thing like a flat head screw driver or the multimeter probe and continue scratching the circuit until it breaks.

The result

*img.techpowerup.org/130716/2013-07-16 21.20.06.jpg

You can coat the scratched area with varnish(for the looks)-Optional

*Step 4*Now connect the PCB again and reassemble everything. Connect headphone or speaker. If you connect speaker, set the amplifier volume to full. Test using USB drives-copy, move etc, do random stuff.

Here's my result. Beware of some loud Linkin Park near the end of the video.

*youtu.be/IdfZ80JG2cg

Enjoy.


----------



## harshilsharma63 (May 2, 2014)

Nice tutorial  I am facing this problem too Will try the procedure in some days.


----------



## anirbandd (May 13, 2014)

very nice tutorial bro!!


----------



## itsakjt (May 19, 2014)

harshilsharma63 said:


> Nice tutorial  I am facing this problem too Will try the procedure in some days.



Thanks.  Do try it. You will be able to know through a quick testing also. Just open the chassis and unplug the front panel USB header cable. Keep the audio cable plugged in. See if the noise is gone. 



anirbandd said:


> very nice tutorial bro!!



Thanks anirbandd.


----------



## Nerevarine (May 19, 2014)

Earned the like, excellent tutorial


----------



## itsakjt (May 21, 2014)

Nerevarine said:


> Earned the like, excellent tutorial



Thanks a lot.  That noise was horrible. I did not know of it till 2-3 months of buying the new Asus M5A97 R2.0 motherboard, just a slight whining noise was there which changed according to system activity. It was irritating. One day, I was copying something to my flash drive while listening to John Denver and then OMG! That floppy drive-like noise blew my heads off! I immediately cancelled and retried. Same results every time. Then I turned off power and removed the front panel USB wires, no noise! To check the motherboard, I took a spare front panel header bought from footpath. Connected just the USB plugs of it and the audio plug was from my chassis thus making the two separate. No noise. I was sure then.


----------

