Whine In E1705

I just noticed in my E1705 that when I plug in the power adapter the system starts a low pitch whine. This whine starts whether the E1705 is on or off. When I unplug the power adapter the whine slowly goes away. What is up? Do I have an issue with the adapter or the battery or what? HHHHEEEELLLLPPPP

 

I am now chatting with a support rep. I will post the outcome.

 

OK. After an hour long chat, remove and replace the battery. That should stop the sound. If not you may have to replace the ac adapter and the mboard.

 

What happens when you plug in AC adapter only, not to laptop? No whine?

What happens when plugged into laptop but no battery installed?

The AC adapter may buzz/whine when only under load?

 

I was going to say it is related to the CPU buzzing under certain conditions, but you say it does it when on or off.... So that points to the charging circuit inside the machine, or maybe the battery if the sound is coming from the lappy itself and not the a/c brick. Try removing the battery..

Oh, another thought .. the A/C brick may not be outputing under load correctly... that would cause strange things to happen.

If it was me, I'd get Dell to send a replacement A/C brick if it's doing it with the battery removed...


Just so it may help other people, if the system is making noise powered ON, this may help:


"This seems to be a pretty common problem with the Core 2 Duo processors, when they are idle they make a high pitched buzzing sound. The solution that works for most people is to install RMClock and check "Run HLT Command when OS is idle"

You can download the RMClock program @ http://cpu.rightmark.org/products/rmclock.shtml

Make sure to check "Run HLT Command when OS is idle (restart required)" under the "Managment" file.


Another related post for those having the cpu whine:

http://forum.notebookreview.com/showpost.php?p=1652387&postcount=12
The problem is one which is reasonably well known to MacBook users. It affects a Dell 6400 I have, and I think I would go insane if I ever actually used the laptop.

The noise is caused by the CPU switching between power states. That is why it is not apparent when you are putting the laptop under load - the CPU is not dropping down into the lower power states. The only solution that I know to work is to get RMClock and enable the option 'Run HLT command when OS is idle'. That solution works because it forces the CPU to go no lower than the C1 power state. The same effect can alternatively be achieved by disabling USB power management or plugging in a USB device.

The caveat of forcing that option is that the battery life will decline significantly. Other solutions have been proposed which avoid reducing battery life (see the third link, for example) but they did not fix the problem for me.

http://www.engadget.com/2006/03/14/w...ure-not-alone/
http://www.engadget.com/2006/07/08/a...-macbook-pros/
http://forum.tabletpcreview.com/showthread.php?t=2674
http://forum.tabletpcreview.com/showthread.php?p=31347
http://www.red-sweater.com/blog/105/...et-macbook-pro

 

Thanks all. I don't know what happened but after the Dell tech came out and replaced the motherboard and the ac adapter...no longer whining. I will continue to monitor the situation and report back later. Thanks again.

 

It would have answered a LOT of questions if the tech had just swapped out the AC adapter before changing out the motherboard. Switching power supplies are notorious for noise if not right.

Interesting stuff from Wearenotalone on the CD2 noise...

 

Did you check to make sure that your battery is not 1 of the ones being recalled?