Spark Codec Plus - Mics no lights / Background noise

[alynch30]

We have a few Cisco Spark Codec Plus installed now.

There is an issue on one of them...

1- There is a strong background noise coming out of the room when we are on a call... No particular noise in the actual room though other then standard sound masking.

2- (In-Call) The lights on the 2 microphones are not working.. No green(unmuted), no red(muted). The actual mute buttons are not working either.. Nothing happens when I press them ... The only way to mute the mics is to use the touchpad but then again no lights are coming out of the mics mute buttons.

I tried to compare the settings with another room with the same setup - All the same! The mics version is "Table Microphone 20" just like the other room.

Background noise is still present if 1 of the 2 microphones is connected no matter what mic input I use.

The other Spark Plus we have are fine.

[scottcotton]

The microphones require a TRRS cable to allow the mute/un-mute function to work, as well as the LED indicator around the mute button. Chances are, there's an extension cable that's been used that isn't TRRS (instead it's only TRS). A TRS cable will exhibit the same behavior you've described whereby the LED indicator won't work nor the mute/un-mute function from the microphone.  The image below shows it a little bit. Look for 3 black spacers on the male end of the extension cable. If it's only a TRS cable, you'll only have 2 spacers.

The noise could be a faulty mic, our faulty cable / connection. See if the issue follows one particular mic. The other possibility is the microphone cables are running in parallel to a high voltage cable whereby 'noise' is being injected into the low voltage cable.

[alynch30]

The noise does not follow any particular mic or input.

I have an extra mic at my desk. I'll give your theory a shot tomorrow by disconnecting the current microphones and connecting 1 bypassing the extensions.

I'm also curious to see if it makes a difference for the noise.

Thanks,

[NDEX]

Sounds like a possible faulty CODEC or CODEC setting.

If all the following are true then try reloading the same firmware then if problem persist try an upgrade or downgrade to the same version as all the other systems that are working correctly.

1. If You are using the Table Microphone 20 with the attached unaltered cable with a TRRS 4-pin mini jack connector then there is no easy way to test the mic unless you have another known working codec onsite. but start with a visual inspection and if it looks good assume it is good until you rule it out.

If you have the correct cable and the Mute/Unmute LED is not working I would assume the mic or the

ports on codec are faulty and replace the mic and test ports on codec.   

2. The same sound is present regardless of using mic input 1 or 2

3. The same sound is present even with no mics plugged in

4. You try a different mic and get the same sound.

If any of the above test has any effect on or changes the sound then it must be the mic, cable path or settings.  

[Wayne DeNardi]

You mention that there are extension cables involved.   These are likely the cause of the issue.  As @scottcotton pointed out, you need to use the 4-pole cables/connectors.  The Cisco Part Number for a genuine mic extension cable is CAB-MIC20-EXT.  If you're using a standard stereo 3-pole connector, then this shorts out the mic control and ground, so the mics will not get power hence you just get noise and the mute button will not function.