[Ti] noise from Ti only during battery use

[Jerry Krinock]

on 03/04/11 01:47, Don at ds1000309 at uid.onemain.com wrote:

> Greetings...
> 
> I've recently noticed that when I operate my Ti 400 on battery power, I get a
> high
> pitched noise which is electrical (versus the sound of, say, a drive going
> bad). It
> gets louder the longer the 'book runs and stops as soon as I plug in the power
> adapter.
> 

Inductors in power converter circuits can do this if they come loose, also
if something is starting to go bad.  I'd say you have a non-phony "orange
alert".  Think about AppleCare, daily backup, loaner machine to use during
repairs, etc.