T23- frequency from exhaust opening when powered OFF.

[dsigma6]

I did plenty of searching but couldn't find anything..

T23 was plugged in last night when I fell asleep, and was hibernating when i woke up. I couldn't help but hear the usual high pitched frequency when I got closer to it. I put my ear up to the fan area and it was definitely coming from inside. My question is why is there a noise in there when off, but plugged in? Could it be a power issue on the motherboard?

[Thinkpaddict]

Maybe it is the charging circuit? Test this with a full battery so that the charging circuit will be inactive.

[dsigma6]

Test this with a full battery so that the charging circuit will be inactive.

it was tested with a fully charged battery, but maybe since the battery is old it is confusing it. either way it shouldn't be making noise!

[rkawakami]

Generally noises like you describe are coming from a coil or a transformer in the power supply circuit. The next time it happens, carefully remove the battery (if possible) without disturbing the laptop too much. Either that, unplug the AC adapter and see if the noise disappears. In order to permanently get rid of the noise you will have to find the offending part and then either physically "tweak" it or replace it. By tweaking, this could mean resoldering the part to the board, flicking it with your finger, encasing it with a non-conductive hot glue (the kind typically used around oscillator circuits), etc.

[dsigma6]

Thanks Ray- As always, your knowledge is more than helpful. So I take it that this is just another one of those nuisances that really isn't anything to worry about. The noise immediately goes away when the AC is pulled.

edit- The noise occurs if it has any sort of power- either battery, ac, or battery and ac.

[dsigma6]

I wanted to just suck it up and deal with it, but this is starting to get to me. Not the frequency, but the fact that because of this problem, my battery drains about 5-8% per day if not on the AC.

Ray mentioned finding the culprit, but I'm not quite sure if I can pick up the noise and pin-point it. Not like I'm actually going to see something moving in there...right?

[rkawakami]

my battery drains about 5-8% per day if not on the AC.

Is this with the laptop completely turned off? And does it matter if the battery is removed from the laptop and left alone for a couple of days? If you do this and the battery still drains, then I would say that it's old and just discharging normally for its age. If it only loses charge when installed in the laptop, then there is something in your system which is drawing power when it shouldn't.

<snip>... but I'm not quite sure if I can pick up the noise and pin-point it. Not like I'm actually going to see something moving in there...right?

Correct, you wouldn't be able to see anything vibrating that fast. An old trick I remember from working on car engines (when microprocessors didn't control them and you could actually see the entire engine) may apply here if it is possible to operate the laptop with the keyboard lifted up. You would need a fairly long (1 foot), thin (1/8 to 1/4 inch), non-conductive probe which you could touch down onto the components of the laptop. The other end would be held against/near your ear (remember: nothing smaller than your elbow should be inserted into your ears!). The conductive path provided by said probe should help you isolate the offending part. What comes to mind is a chopstick, altered with a file or Dremel on the small end so that it is more pointed.

[dsigma6]

The reply I was looking for has arrived! I have removed the battery for extended periods, and upon using it again it was still at 100%. If the battery is installed it will make the noise. I am talking about having the machine off with the battery installed, that's where the power drain takes place. It's a real annoyance having to remove the battery every time I'm done using it..

You present a good idea for finding the source, I will try that when I find the right tools.

Looks like I'm getting Japanese food tonight..

Thanks Ray!,
Dan