in ThinkPad: T400 / T500 and newer T series Laptops https://forums.lenovo.com/t5/ThinkPad-T400-T500-and-newer-T-series-Laptops/T400-Loud-buzzing-noise-when-plugging-in-AC-adapter-amp-charging-battery/m-p/169822 ThinkPad: T400 / T500 and newer T series Laptops topics Thu, 29 Oct 2009 04:06:52 +0000 tp01_en <![CDATA[ ]]> https://forums.lenovo.com/topic/findpost/1300/169822/169822 Hi, I've had my T400 (2764-CTO) for 9 months.  It came equipped with the standard 4 cell battery and 90W adapter; I've also picked up a 9 cell battery and 65W travel charger.

 

Here's the skinny: when I plug the adapter in to charge the battery, the laptop emits a buzzing sound for ]]> Thu, 29 Oct 2009 04:06:52 +0000 https://forums.lenovo.com/topic/findpost/1300/169822/169822 yakisoto <![CDATA[ Re: T400 - Loud buzzing noise when plugging in AC adapter & charging battery ]]> https://forums.lenovo.com/topic/findpost/1300/169822/169923 Yakisoto,

 

Interesting that it occurs with both batteries and both AC adapters.   To be clear, the sound occurs only when the battery has less than 95% and is charging?  (We reduce the charge rate at around 95-96% to "slow down" the charging and take it easy on the ]]> Thu, 29 Oct 2009 11:59:16 +0000 https://forums.lenovo.com/topic/findpost/1300/169822/169923 Mark_Lenovo <![CDATA[ Re: T400 - Loud buzzing noise when plugging in AC adapter & charging battery ]]> https://forums.lenovo.com/topic/findpost/1300/169822/169936 My AC adaptor on my t500 makes a constant buzzing noise whenever it is plugged and charging

 

I thought it was both but I managed to pin point it to the adaptor, and the adaptor gets very warm.. almost hot, is this bad?

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Thu, 29 Oct 2009 12:54:12 +0000 https://forums.lenovo.com/topic/findpost/1300/169822/169936 chris001
<![CDATA[ Re: T400 - Loud buzzing noise when plugging in AC adapter & charging battery ]]> https://forums.lenovo.com/topic/findpost/1300/169822/169998 Thanks for the replies. 

 

Mark, yes, the threshold is 95% - if I plug in while the battery level is above that (not charging), there is no sound.  I've got the LED backlight (are you thinking it could be the inverter?); I've pinpointed the sound with a stethoscope to the area surr ]]> Thu, 29 Oct 2009 15:28:21 +0000 https://forums.lenovo.com/topic/findpost/1300/169822/169998 yakisoto <![CDATA[ Re: T400 - Loud buzzing noise when plugging in AC adapter & charging battery ]]> https://forums.lenovo.com/topic/findpost/1300/169822/170127 I've also been having the same problem with my T400. It is about the same age (recieved it in mid January 09), and has the same battery (4-cell). The sound is definitely not coming from the adapter, seems to be from the area where the screen is hinged to the body of the machine. My screen is L ]]> Thu, 29 Oct 2009 21:16:10 +0000 https://forums.lenovo.com/topic/findpost/1300/169822/170127 jsad <![CDATA[ Re: T400 - Loud buzzing noise when plugging in AC adapter & charging battery ]]> https://forums.lenovo.com/topic/findpost/1300/169822/170585 Yup, sounds like the same laptop.

 

I did some testing under various power modes: With both the OEM 90w and travel 65w adapters, both batteries made the kazoo sound in all 4 power modes: full on, sleep, hibernate, full off.  I did a quick audio recording of the sound in case anyone ]]> Sat, 31 Oct 2009 05:18:18 +0000 https://forums.lenovo.com/topic/findpost/1300/169822/170585 yakisoto <![CDATA[ Re: T400 - Loud buzzing noise when plugging in AC adapter & charging battery ]]> https://forums.lenovo.com/topic/findpost/1300/169822/993781 Hello, I am having this same issue with my T400. The "kazoo" sound is driving me nuts... Earlier it was inter-mittent, now it is happening all the time when charging battery. If I take out the battery, the sound goes away.

 

Were you able to resolve this issue?

 

Thu, 17 Jan 2013 18:19:22 +0000 https://forums.lenovo.com/topic/findpost/1300/169822/993781 markandrews <![CDATA[ Re: T400 - Loud buzzing noise when plugging in AC adapter & charging battery ]]> https://forums.lenovo.com/topic/findpost/1300/169822/4547764 Hi guys... I'm sorry for reliving this post, but I have the same problem in my Ideapad L340 Gaming 15 IRH :( did you get a solution?

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Sat, 12 Oct 2019 04:15:53 +0000 https://forums.lenovo.com/topic/findpost/1300/169822/4547764 Paco93