[SOLVED] 5V PoE generates annoying sound (youtube)

Official Hardware Classic Yún
21

Great news VinzzB

Makes me wish that mine was soldered into a socket and not direct in the board now.

22

no problem guys im glad you have solved your issue.

just to let you know the Ag9050-s, Ag9605-2BR, and the 9705-2BR are all compatible with this board. (although arduino advertise the module they sell as A Ag9605-S it is infact a Ag9605-2BR) we recommend the 2BR variants as they have input bridge rectifiers fitted that allow it to work with a PSE that has a reverse polarity output.
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We would normally recommend a 470uF but in this application you can get away with about 100uF.

if you have soldered it directly you can still solder a cap across the output pins of the module ether like VinzzB or like our original post:

https://dl.dropboxusercontent.com/u/23654687/Arduino%20Yun%20Tantalum%20Mod.jpg

23

Perfect thanks for that Wigouche.

This information should be moved to the playground under the POE section so others know. Both regarding the modules and the fix.

Also confirmed that it worked on mine as well.

24

Thanks @wigouche and @VinzzB, did the same mod to the Yun's POE module.

25

wigouche:
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We have informed Arduino of this mistake, in a hope that they will correct this mistake on the next revision of their Yun board.
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Arduino Yun's mistake? I try to find out why? here is my guess:
Arduino Yun has famous USB output voltage bug, here is side effects of that bug, generates annoying sound.

26

sonnyyu:
Arduino Yun 5v pin/USB port doesnt provide 5 volt.

Arduino Yun 5v pin doesnt give me 5v. - #6 by sonnyyu - Arduino Yún - Arduino Forum

4.48 volt at 5v pin will cause some shield fail, and low voltage at USB port cause a lot of USB device fail.

Arduino Yun release 5 is fixed 5v pin/USB port problem, provide exactly 5 volt which I saw the demo at maker faire nyc yesterday.

The new Yun release 5 should fix this problem?! It will make it quite.