Hi everyone, absolutely nothing wrong with my device (And trying to keep it that way!) - so far it has been amazing, but this morning i have an interesting issue!

I'm charging it at work using the mini-usb to old nokia converter, and have it plugged into my E71 charger (Small round connector type).

And it makes a really high pitched squeal of a noise.. Hard to explain, but a bit like gas escaping form a coke bottle when you open it - but higher pitched! Quite quiet, and no dogs have appeared at my window yet - but they might do!

I've un-plugged it for now, and going through the PC USB connector - no squeal...

Anyone else tried using that chargin method, and any other noises?

Yes. It woke me up the first time in the in the middle of the night. It usually happens when it is close to a full charge.

thats really interesting and yes it's nearish a full charge.
Wonder if this is possibly causing issues to the device? eeeeek

I usually find this happens on any of the fast chargers - i.e. with the higher outputs. I've had it on my last few Nokia phones. I even had to dig out on older charger to useif I was sleeping, just so it didn't whine and squeel. It always sounds to me like it is trying to force the power in and constantly changes pitch and pulses as it charges (but tends to be more quiet when charging) - as soon as charging finishes, it makes a right racket!

However I don't believe it damages the phone - I can imagine the battery life may be affected from being charged so fast, but you would also assume that Nokia have built that into the battery/charging circuit designs.

I tend to be able to hear dog whistles - so this might not be as bad for some people! Pretty interesting though. The phone I currently use is an E65 (because my N900 has been sent away for repairs!) - and it whines like crazy with the charger that came with it!

It's probably/most likely the AC/DC conversion circuitry making the whine noise.

Edit: The noise will become louder with cheaper capacitors... ahem Nokia....

I too experience this problem and woke me up the first time!

Very odd, but glad to hear it isn't likely to damage my phone.

> And it makes a really high pitched squeal of a noise

I'm another experiencing this auditory onslaught. It happens in both of the following situations:

i) Using the n900 supplied charger. The electronic wailing appears to come from the plug/charger itself.

ii) Using my previous N79 charger with the supplied USB adaptor. Note that this charger was able to charge the N79 in blissful silence.

Consequently, my N900 and I are no longer sleeping together - I've thrown it out into the spare room, it can get up to its noisy overnight charging antics there.

No other faults with the phone otherwise, and very pleased I am with it too.

Spann

I have had thisissue as well. its quite annoying. One can dampen the noise by putting it on some material that "sucks" up the sound. I for one used a handkerchief package.

Wow quite a few people with the same issue
Wonder if Quim or someone in the know could pester nokia to see if it's a known fault that we have to live with or if it's an unknown to nokia issue and they could get some brains on it?

By the sounds of it, it's not a huge problem, apart from the N900-User Divorces at night

As was mentioned, this is caused by the switching circuitry in the charger as it regulates the output. Here's a little read on it i found with a quick google: linear vs switching chargers. Note that the "noise" the article talks about is EMI (electromagnetic interference), but it's clear that certain components can translate the electrical noise to acoustic noise. Also note that, as some people have observed, the noise becomes more pronounced as the battery is nearing full and the charger reduces the output to it. My LG charger does this, becoming very noisy when the phone isn't plugged in or the battery is full. I can also hear the noise of the power circuitry in my flat panel, and CRTs are audible to me when on. This is all due to electrical noise being converted to acoustic noise through one or more components.

Maybe Nokia will go to the dual mode charging circuitry the article talks about for their next flagship. I expect not, though. :/