Loud hiss on the output comes and goes

[gorasou]

Hi

I have a really weird issue with my Radio Music. There is a really loud noise on the output that's even louder than the files themself. thing is that it's gone sometimes, giving me a perfectly clean signal. I really don't know what the problem could be or what to do as I'm not a experienced diy-er. it worked fine for a couple days until there was hiss for the first time. and now sometimes it's there, sometimes not...

I hope someone can help out, thank you in advance.

Marc

[TomWhitwell]

Hi!

Please read #50 and see if it is same problem.

If it is definitely hiss (ie high frequency white noise) and not hum (ie 50/60hz buzzing) then please record the effect and upload a link here.

[gorasou]

It's not the same problem unfortunately, I already tried that :(

here's an example for the noise. it worked a couple hours ago but now it's back on...

https://www.dropbox.com/s/gqzuvhagbebstu0/Radio%20Music%20Noise%20Probelm.wav?dl=0

[TomWhitwell]

Thanks, I haven't heard that sort of problem from anyone before, particularly if it is intermittent.

It sounds like a high-pitched hum, different from the mains hum that some people experience when working across cases, and different from the noise that a few people have experienced when adding very quiet samples.

And - it is inconsistent, so unlikely to be a simple hardware problem within the actual module.

Not sure what to advise, you could try:

• checking all of the connections on the board
• trying to understand what causes it to come and go
  • Do you have other bits of equipment that are sometimes plugged in?
  • Lighting, or cooling or other electrical noise-generating devices nearby?

Without any more information, I don't know what to suggest.

[michaelhaeusler]

Hi,

I am having the same problem. It is the same hum and clicking sound but it is much louder compared to the sound from the SD-Card. The humming is always there . When the SD-Card is removed it changes it's frequencies (1 octave higher) und and is shortly interrupted periodically (every two seconds).

I checked the module with the module hardware test and everything works fine and no noise is present but as soon as I install the RadioMusic Firmware (v1.1) the humming is there again.

@gorasou Did you find a solution for the problem?

[Thonk-Steve]

michaelhaeusler is this definitely the same problem do you think? if your noise is not intermittant as gorasou reported? Does it sound identical to the soundclip that gorasou supplied?

[michaelhaeusler]

Yes, only that the noise is louder compared to the sound. Apart from that the hum sound is exactly like the soundclip from gorasou only that I have an additional periodical clicking sound and it is always there. I can provide a soundclip this evening.

[Thonk-Steve]

I'll admit I'm baffled too as I've never come across one like this. gorasou and michaelhaeusler, it's probably worth posting photos of both sides of both PCBs.

[michaelhaeusler]

I'll will provide some photos tomorrow. Here are the noises - the first with an SD card the second without:

https://dl.dropboxusercontent.com/u/3398946/radio_music_noise.mp3
https://dl.dropboxusercontent.com/u/3398946/radio_music_noise_without_card.mp3

[michaelhaeusler]

So I finally made it to make some photos of the PCBs. Unfortunately the problem still exists. I double checked all soldering but the noise is still there. As I said there is no noise when doing the module hardware test so it might have something to do with the card reader?

Here are the photos:
https://dl.dropboxusercontent.com/u/3398946/IMG_2371.JPG
https://dl.dropboxusercontent.com/u/3398946/IMG_2372.JPG
https://dl.dropboxusercontent.com/u/3398946/IMG_2373.JPG
https://dl.dropboxusercontent.com/u/3398946/IMG_2374.JPG

[breedx2]

One of the yellow capacitors next to the power bus header looks like it's poorly soldered from the top of the board, and from the bottom I can't even tell what's going on there -- looks like a gashed open hole. Fortunately, it looks like the traces are just on the top...

I would definitely touch that up with some solder from the top and then do a continuity check to make sure it's going where you think it should be going.

[TomWhitwell]

Closing after inactivity

[michaelhaeusler]

Sorry for my very late reply. I had re-checked all solderings back then as breedx2 had suggested and made the continuity check but without success. The loud noise is still there which makes the module unusable. I had given up after that because I had no idea how to continue. Is there anything else I can do? Is it maybe possible that one component isn't working correctly? As I mentioned the noise is not there when doing the module hardware test. So maybe the SD-Card reader is somehow faulty? I am grateful for any kind of help!

[djamsia]

I recently set up a Radio station.
there is no silence when no sounds, there is always a ground noise.
also get a loud hum from the reset input. when it used as an output.
I have the pcb rev2.1