C80 Clicking noise recording through built-in monaural mic

[dru_nasty]

I'm getting a constant faint clicking noise in my playback specifically from the channels I set for the built in monaural mics. It doesn't matter in AF or MF mode with the lens either. I have a DJI wireless 3.5mm for channel 1 & 2 and channel 3 & 4 as a scratch track using the monaural mic. If i isolate my DJI tracks, the audio is perfectly fine, it's just the monaural with the clicking noise. I was shooting throughout an entire 2 floor office building, many clips and interviews and every single one has the audio click issue.

Even more strange, when i bring the clips into Premiere is when i noticed the clicking during playback on those two channels. But if I simply open an MXF file in my VLC player the clicking is not there.

This is obviously extremely annoying, as i've just purchased this camera. Any ideas what can cause this and how to fix it? I need to have some type of monaural backup.

[AtticusLake]

Sorry to hear about your problem,.  I have the C80, and while I haven't used the built-in mic much, I haven't noticed that issue.  In fact you can hear a sample I recorded here: https://vimeo.com/1052645939  @ 03:42

I can't remember what channel assignment I used, but I think it was the built-in mic on channels 1&2.

It may be some kind of interference?  Was your cellphone on?  Or possibly something loose rattling on the C80 body?  A sample might help.

If you're not hearing it in VLC, it may be that VLC is just playing channels 1&2.

[dru_nasty]

While recording, I can't hear the noise at all. Confirming that AF is off on the lens. This is just during playback that i hear it.

I uploaded a sample here: https://www.youtube.com/watch?v=l_kejRe5TFo

The audio tracks you're hearing are track 1 & 2 from the built in monaural.
The original clips i had issue with i was filming in an office building in NJ. The sample clip above is in OH.
It's the same sounding interference. The only constant is there is WIFI in both locations I was filming.  

Could it be something within the camera that's loose that i just don't hear while filming?

[AtticusLake]

I guess you mean the kind of constant "sizzling" all the way through?

Doesn't really sound like interference -- it's almost like the fan has a bad bearing.  Was the fan on?  Does it go away when you turn the fan off?  (Go to System Setup -> page 9 -> Fan Mode -> Auto)

[dru_nasty]

Yes, the constant sizzling/crackling noise. I tried it with fan mode auto and always on and it's the same result. It does not go away when fan mode is auto.

[AtticusLake]

If it's not the fan, then I'm afraid I'm stumped.  It really does sound kind of mechanical, and the fan is the only thing moving in there, afaik.

Jut make sure than when fan is "auto", and you press record, then the "FAN" icon in the display should go off.  If the sound is still there, then like I said, I'm stumped.

[dru_nasty]

Well thanks for helping me work through some potential causes. I'm wondering if anyone else has had this issue, and if i should see about returning this camera.