It helps if you can identify the make and model of your computer.
I assume a laptop from the problem description.
The Laptop likely has a Lion Battery.
The noise you hear can be the result of several related issues.
Bad or fully discharged battery. On some laptops, the power supply goes into
sort of a burst mode when it has an attached battery that is very low.
Discharging LI batteries to such a low level is not recommended, and can
damage the battery, reducing it's capacity.
It's also possible that the Laptop's power supply (a combination of internal
circuitry and the usual "wall wart" can be starting to fail.
In some cases, (some ACER laptops and possibly others) it may be necessary
to reset the battery monitoring circuitry. ACER documents a method to do
this on the Acer Web site, or by calling Acer service. The method is model
dependent.
An Li battery self discharges, and also provides "keep alive" power to the
laptop. The self discharge rate seems to be much higher than with the older
Ni Cad batteries.
This can easily result in a very low battery in just a couple of weeks, if
the laptop is not used or plugged in.
I have one of the "netbooks". This had a similar problem, in that after
setting unused for about three weeks, the laptop refused to charge the
battery, and showed a fault condition by flashing a red charge indicator.
The laptop would powerup, start the boot process, and shut down with the red
charge indicator flashing.. Finally, I had to charge the battery with an
external charger, put the battery back in the laptop, and reset the battery
monitoring circuitry.
