Strange noise with T40

[likely]

i've noticed an electronic rattling noise coming from the upper left area on my t40. it only happens when the power adapter is unplugged and the unit is running on battery. at first it thought it was a bad battery so i bought a new one. same problem. so now im guessing its the laptop itself. the noise level is slightly louder than a clicking hard drive, and sounds distinctly different.

any idea how to fix this? should i call ibm and use its warranty? i think theres a few months left on its warranty, but will they even fix something like this?

[roberts5]

does it go away if you hit the mute button. I have something similar that seems to just be electrical noise hitting something.

[likely]

no it doesnt go away. i took the keyboard halfway off and powered on the laptop for an unobstructed listen. the noise is definately coming from the area where the battery connects with the computer, though im sure it's not the battery itself. im thinking about just giving it to ibm for maitenance before the warranty expires. i just hope this is something they can fix/replace.

[raabjerg]

You might try disabling power management on the USB root hubs (in device manager). On my old T42, this made a great difference wrt. a similar noise.

[likely]

raajerg, how exactly do i do this? there are four root hubs and their tabs read general, power, driver and power management. within those tabs though there arent any options to disable. i can disable from the main menu but that would just turn off the device i think.

[raabjerg]

For each root hub, go to properties and the power management tab. In this tab, there should be a checkbox saying something like "allow the computer to ..." (I don't have the exact english wording, as I'm using a non-english windows).

Make sure these checkboxes are unchecked (i.e. that power management is disabled)