Strange noise from my T41p...

[Chatbox]

Laptop: Running from battery only, in Windows. Wireless (802.11b) is on, Bluetooth is off. Wired NIC is not plugged in. No PCMCIA cards in slot. CPU load is between 0 to 1%. No CD in optical drive.

Noise: Quite Faint (or very faint if you have not so good hearing), high pitch. Noise from left hand side of the keyboard, near the air vent. The pitch is not constant, it goes on and off, kind of like moss code. (no, it's not the cooling fan, neither is it the harddrive).

Note: Turning 802.11B didn't make a difference (not that I should hear it anyway - 2.41xGHz).

Question: Can you hear it on your thinkpad when you have your ears just inches away from the keyboard?

[K. Eng]

Yes, I can hear exactly what you describe from my T40 if I am in a very quiet room. The noise is pretty high frequency and older folks or those hard of hearing often cannot detect it.

I managed to isolate the problem to the ICH4-M part of the 855 chipset after reading of a similar problem in the Dell Latitude D series.

The only way to make the noise go away is to disable USB controler power management in the Windows Hardware Device Manager (Control Panel -> System Properties, Hardware Tab, Device Manager button).

Unfortunately, this raises the system's power consumption, and I have noted a 30 to 40 minute decrease in battery runtime using this solution.

[1llogic]

hi, i just got my notepad today and i noticed the same problem when im not using AC power. the hissing noise is quite annoying; but you're right.. you can only hear it in a very quiet place.

i wanna get rid of this problem asap, but i have one question. can you explain in detail how to disable the USB? because i followed your steps, and there were 3 usb stardard universal pci to usb host controller, and another 3 usb hub options. which one do i disable? as you can tell, im quite a newbie and any help would be greatly appreciated.

[T41mbi]

id say its the system board causing the problem you describe

[1llogic]

are there any solutions to this? its becoming a huge problem because i spend a lot of time in the library, and the noise is so unbearable.

[T41mbi]

call IBM - its either going to be the system board or inverter card that needs replacement...

I spilt water on my lappy, it was making a hissy noise every now and again just randomly, it wasnt the fan, the ram, nor the hard drive... i sent it to them, they replaced the inverter card and all is well...