My Sony VAIO A517S gives a high frequency sound time to time.
First I tought it is because of the charging of the battery, but even if I removed the battery and ran the laptop on only ext. power it continued whistling. It is not a loud sound but it is annoying, because it is a high frequency noise.
I also tought, that it might be because the processor is running on high speed, but when I go to standby my VAIO continues whistling. The noise seems to come from near the ext. power connector. If I remove the external power supply it stops whistling immediately.
Any idea?
