Z77 Extreme4 problem with LAN LED, it creates noises

[Reinhold]

Hi.

3 month ago, I build my own computer using the "ASRock Z77 Exreme4" motherboard.

ever since day one, I've had a problem with an annoying, tinnitus-like hizzing noise coming from my computer.

It is obvious that it has something to do with the LAN LEDs because:
- The noise is in rhythm with the activity LAN LED. when it lights, the noise get louder.
- When deactivating the onboard LAN card in the Windows Device Manager, the noise immediately dials down. the activity LED still blinks, and the noise still follows the blink.
- The LAN activity LED blinks at the same rate as the activity LED on the router, and the noise follows that LED as well (ofcourse).

Using the "Good Night LED" option in the ASRock BIOS doesn't help. Only the Power LED stays off, the option doesn't seem to have any effect on the LAN LEDs, even though it says so in the description.

I've tried RMAing the board to the retail-store. Disassembling the computer, and sending in the motherboard. But they said they couldn't reproduce the problem, so it got turned down.

What am I suppose to do?

This is the complete build:
Motherboard - ASRock Extreme4 Z77
SSD - Samsung 840 Series MZ-7TD250 - 250 GB
HDD - ST3320620AS ATA Device - 500 GB
Sound Card - Creative SoundBlaster Audigy
RAM - Crucial DDR3 BallistiX Sport 16GB KIT 2x8GB
CPU - Intel Core i5-3570K
GPU - Gigabyte GV N66TOC-3GD - Geforce 660ti
PSU XFX ProSeries P1-750B-BEFX Black Edition Full Modular (Gold)
Case - Nanoxia Deep Silence 1


Thanks in advance, Reinhold
(And sorry for my poor english)

[odiebugs]

Re: Z77 Extreme4 problem with LAN LED, it creates noises

A few questions.

Did you put the board against the standoffs on the case or did you put a plastic washer between them ?

Are you sure you don't have a standoff in the wrong place ?

Have you removed the sound card and used the onboard sound, if the sound is coming from the speaker. ?

Is the sound coming from case or from your sound in speakers ?

Does your CPU have graph, can you remove the card and use onboard graph.

Is the retail store a asrock store or repair shop, if not and you can't isolate the problem, you need to send it to asrock.

If the store really tested it, maybe your PSU is causing the problem, if they didn't hear a problem.

[parsec]

Re: Z77 Extreme4 problem with LAN LED, it creates noises

As Odie asked, is the noise coming through the speakers or headphones? That is where the usual audio signal interference is noticed, in the audio output signal itself.

Please understand that the LAN LEDs are not making the noise, it is the LAN signal or activity that is adding the noise to the audio signal. The LAN LEDs light up when there is activity in the LAN electronics, which you also see in your router. The LAN LEDs are very simple, they don't create any electronic noise, compared to all the LAN circuitry.

When you disabled the onboard LAN, I'm guessing you still had the the network cable from your router connected to the onboard LAN network jack. So the router was still sending network signals to the onboard LAN controller, although the board was not using them. But part of the onboard LAN electronics was still active, and doing some processing of that network signal. That is why you still had some noise after you disabled the onboard LAN controller, it can only be disabled partially.

Try disconnecting the LAN cable from the router to the PC, and see how much noise you have. Yes, you won't see the LAN LEDs flashing, but that is because they are not getting any signals from the router. If you could turn off the LAN LEDs, you would still have the same noise, IMO.

Do you have the same noise problem if you don't use your Soundblaster card?