BT Whole Home Mini weird squeaking noise

[alyduncan]

Hi, one of BT Whole Home Mini discs makes an awful squeaking noise meaning it’s unusable.

I bought a pack of three a few months ago and had been using two, which were fine with no noise.

Yesterday I set up a third to improve the signal in the kitchen but it is making the noise despite being reset a couple of times. What can I do? Thanks

[Paul608085]

Is it definitely the disc, or the power supply? If the power supply, does it still make the noise when plugged in to the mains, but not the disc? (I ask this because I have a different device whose power supply makes a clicking noise when connected, but not when the device is disconnected - the device itself is faulty and shorting out the power supply).

Either way, you say you bought them "a few months ago": are they still under guarantee?

[alyduncan]

Hi Paul

Thanks for the response, I have tried it in a couple of sockets and it still makes a noise unfortunately. I only got it in November so should still be in warranty. Guess I will contact BT and see what they say.

cheers

aly 

[Keith_Beddoe]

The noise is normally caused by wound (copper coils) within the plug top power unit or within the disc itself. These form part of the switched mode voltage regulators which lower the voltage to different part of the circuitry.

These regulators operate at a high frequency which is normally inaudible to normal hearing. What can happen is that owing to a fault in the internal feedback circuitry (usually a faulty capacitor), they can operate in a pulsing mode which causes them to become audible and most annoying, as it caused the coils to vibrate.

You can prove whether its the disc of the plug in power unit, by swapping the power unit with another disc, and see whether the noise is still there. With most consumer electronic devices, its the plug in power units that normally cause the problem.

Either way, you should be able to exchange the faulty disc and power unit.

[alyduncan]

Thanks Keith, that’s really useful - if it’s the plug I might have a similar adapter I can swap it with, if it’s the disc itself I will ask to exchange it. Aly

[Keith_Beddoe]

Try swapping the power supply out with one of the other discs, that would prove it.