# Strange sound issue (static sound) - Philips SHB4000/00



## SaiZo (Feb 16, 2014)

Ok, so I was trying to connect my headphones, the Philips SHB4000/00 to my fiance's laptop, an IBM Lenovo T420s. These are Bluetooth headphones, and work with both smartphones, laptops and even Playstation 3..

However, as fast as I want to use the microphone I get this "static" sound in them.
Thought first that it was the laptop that had issues, so I tested it with the PS3 system. Same there.
And as a final test, I tested it with both my Samsung and Xperia smartphone - still same issue.

The strange thing is, that there has never been any issue with them like that earlier - getting static noise.

When listening to only audio, there are no issues at all.
Should I send them in for repair/exchange or just get a new pair?


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## jcgeny (Feb 16, 2014)

may be they are having some "static electricity" because they were on but without sound a too long time , let them have a night turned off


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## SaiZo (Feb 16, 2014)

jcgeny said:


> may be they are having some "static electricity" because they were on but without sound a too long time , let them have a night turned off


That's not the issue, the strange thing is that whenever I want to have the microphone enabled - the "static" comes on.

Couldn't find my reciept for the headphones, so I opened them. Couldn't find anything wrong with them, however the microphone is tiny, I do have a spare microphone - I could always test and that one instead.
If it doesn't work then, I'll just get another one. Got these cheap. They retailed over here for about 499SEK (say somewhere around US50$), but I got them for half the price since I knew the owner of the store.


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## 95Viper (Feb 16, 2014)

Some types of microphones do not like temperature extremes and/or hard knocks.

If you have a suitable replacement... yep, I would try that... since you already opened them up.
Also, check the output on the thin film battery, to make sure it is at specs. If it is a powered mic, it might not be getting the proper supply it needs.


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## SaiZo (Feb 17, 2014)

95Viper said:


> Some types of microphones do not like temperature extremes and/or hard knocks.
> 
> If you have a suitable replacement... yep, I would try that... since you already opened them up.
> Also, check the output on the thin film battery, to make sure it is at specs. If it is a powered mic, it might not be getting the proper supply it needs.



Funny that you should mention the battery.. Actually the negative cable from the battery is not soldered good enough (if you ask me) to the PCB.
I will test to change the microphone once I get the time, and re-solder the negative side better.


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## SaiZo (Feb 19, 2014)

I changed the microphone, re-soldered the battery, but still get that interference/static noise. Shut down computer and tried, tried it with different mobile phones.
Tried it out in a forest.
Still the same..


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## SaiZo (Feb 26, 2014)

Today I have also gone over all the components to see if there is any part that is "loose" inside it. Sitting there for about 3 hrs with a magnifier (helping hand) and a thin plastic stick.
Still nothing..


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## erocker (Feb 26, 2014)

Definitely seems like a bad connection with the leads coming off of the microphone. Best to send it in for repair.


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## SaiZo (Mar 5, 2014)

erocker said:


> Definitely seems like a bad connection with the leads coming off of the microphone. Best to send it in for repair.



I actually tried without the microphone, still the same.


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## 95Viper (Mar 6, 2014)

Looks like you eliminated everything; but, the speakers, the Bluetooth wireless amp, or the audio amp...  if it is them, then, I would get another headset or RMA that one, if possible.

And, since, you tried it out in the forest... I doubt it is localized interference.

I sort of doubt the speakers, especially if the noise is in both sides.


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## SaiZo (Mar 6, 2014)

95Viper said:


> Looks like you eliminated everything; but, the speakers, the Bluetooth wireless amp, or the audio amp...  if it is them, then, I would get another headset or RMA that one, if possible.
> 
> And, since, you tried it out in the forest... I doubt it is localized interference.
> 
> I sort of doubt the speakers, especially if the noise is in both sides.



The headphones themself work great if only listening to music (media only) but if I turn on the microphone and try and call someone - then it all sounds bad (static background sound).


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## 95Viper (Mar 7, 2014)

Could be in the chip (IC) containing the audio amps, then.
It, probably, has a section in the chip for the mic amp and it is injecting noise (or clipping the signal).

It is nice everything is miniaturized and combined; but, it makes it a bear to troubleshoot or repair at the component level.


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## Ferrum Master (Mar 7, 2014)

It is the firmware. The device works in wrong device mode.

It is a cap mic or a digital one? If a old cap mic, measure the phantom voltage, and put some capacitor after the voltage divider resistor bridge...


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## SaiZo (Mar 7, 2014)

Ferrum Master said:


> It is the firmware. The device works in wrong device mode.
> 
> It is a cap mic or a digital one? If a old cap mic, measure the phantom voltage, and put some capacitor after the voltage divider resistor bridge...



Cap mic. A tiny one, thank god that I was able to find a spare "if" the original one would be damaged.
I'll try what you just wrote, get back if it works or not.
Thanks!


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